Refactor user authorization check for a single project to avoid querying all user projects

See merge request !5102

Warn on failure

## What does this MR do?

Adds styling and HTML for a `success_with_warnings` status in the MR widget. Unfinished as it needs some plumbing in the relevant CI controllers and models.

## Are there points in the code the reviewer needs to double check?

Not at the moment, though I think I'll probably need help getting this to work in the backend.

## What are the relevant issue numbers?

#17669 

## Screenshots (if relevant)

![Screen_Shot_2016-06-29_at_12.02.49_PM](/uploads/af4a915689633fe028f44bb34ae7a5b1/Screen_Shot_2016-06-29_at_12.02.49_PM.png)

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- Tests
  - [ ] Added for this feature/bug
  - [ ] All builds are passing
- [ ] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [ ] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

cc: @ayufan 

See merge request !5004

Speed improvement for builds without DB

Only fetch the images which we are going to use. Speeds up the builds by about 30-45 seconds.

/cc @ayufan 

See merge request !4994

Added checks for migration downtime

This adds a set of checks that check/list which migrations require downtime (or not). It also comes with a CI task that fails should a migration not be tagged properly.

Fixes #14545

See merge request !4911

Merge branch '14284-allow-all-deploy-keys-to-be-retrieved-via-api-regardless-of-project-affiliation' into 'master'

Add /deploy_keys API to retrieve all deploy keys regardless of project affiliation

## What does this MR do?

Add /deploy_keys API to retrieve all deploy keys regardless of project affiliation

## Are there points in the code the reviewer needs to double check?

Is documentation clear?

## Why was this MR needed?

User request

## What are the relevant issue numbers?

#14284

See merge request !4426

Make Service.external_wikis return only active external wikis

Fixes #20067.

## Does this MR meet the acceptance criteria?

- [x] No CHANGELOG since it fixes a RC12 regression
- Tests
  - [x] Added for this feature/bug
  - [ ] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5387

Merge branch '20041-gitlab-workhorse-version-should-be-update-to-0-7-8-in-our-documentation' into 'master'

Update gitlab-workhorse version to 0.7.8 in installation and update guides

Closes #20041.

See merge request !5385

Improve grammar of manual actions documentation

## What does this MR do?

Improve grammar of manual actions documentation

## Are there points in the code the reviewer needs to double check?

## Why was this MR needed?

Because people like good grammar.

## What are the relevant issue numbers?

## Screenshots (if relevant)


See merge request !5382

Revert Content Security Policy

The secure-only cookies setting was causing an issue where the session was
constantly being lost in the development environment.

Revert "Merge branch 'csp-basics' into 'master'"

This reverts commit 9065f9c5, reversing
changes made to f0b446e5.

---

Revert "Merge branch 'remove-csp-sentry-reporting' into 'master'"

This reverts commit 79b02e40, reversing
changes made to f2cd21e8.

See merge request !5381

Remove flaky diff note tests for now

These will be replaced with better, more exhaustive specs by @lbennett based on the conversation in https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/5262.

See merge request !5379

Document when Docker Registry manifest v1 support was added

## What does this MR do?

Document when Docker Registery manifest v1 support was added

## Are there points in the code the reviewer needs to double check?

Is this the best way to document this? We never documented support for v2 or which docker versions we support overall.

## Why was this MR needed?

We made a change and it wasn't documented. Also, it's good to document which docker versions we support.

## What are the relevant issue numbers?

!4669

## Screenshots (if relevant)


See merge request !5378

Clarify artifacts:name default value

## What does this MR do?

Add the default artifact name (`artifacts`) to documentation.

## Are there points in the code the reviewer needs to double check?

## Why was this MR needed?

We didn't document the default artifact name.

## What are the relevant issue numbers?

## Screenshots (if relevant)


See merge request !5377

Use Re-deploy button on Deployments page

## What does this MR do?
Change `Retry` to `Re-deploy` which is more accurate.

## Are there points in the code the reviewer needs to double check?

## Why was this MR needed?

## What are the relevant issue numbers?
Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/18885

## Screenshots (if relevant)

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- Tests
  - [ ] Added for this feature/bug
  - [ ] All builds are passing
- [ ] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [ ] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5374

Fix two small problems on how we handle manual actions

## What does this MR do?
Fixes two small problems in how we handle manual actions:
- On environments page we show a `Play` for the same action that is lately deployed, we should show other actions only
- When we process a pipeline that have only a manual action in a stage, the pipeline will stop being processed.

- Tests
  - [ ] Added for this feature/bug
  - [ ] All builds are passing
- [ ] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [ ] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)


See merge request !5366

Resolve "gitlab:setup rake task fails on 8.8.1 source install"

_Originally opened at !4788 by @rickettm._

- - -

## What does this MR do?

Fix bug #15344, so that the limit parameter that is already passed in to the print_users function is actually used, rather than using a hardcoded value.

## Are there points in the code the reviewer needs to double check?

No, it is a trivial change.

## Why was this MR needed?

This bug causes 100 LDAP users to be displayed even when a different limit is given, which can be annoying.

## What are the relevant issue numbers?

Fixes #15344.

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5364

Remove icons from explore nav

## What does this MR do?
Removes icons from explore `nav/_explore`

## Why was this MR needed?
To match signed-in nav

## Screenshots (if relevant)
Before:   
![Screen_Shot_2016-07-20_at_6.39.01_AM](/uploads/9ccc11d151e37a0ef2fab681ccc07efa/Screen_Shot_2016-07-20_at_6.39.01_AM.png)

After:   
![Screen_Shot_2016-07-20_at_6.43.15_AM](/uploads/ae058b19cc3c887bccf6c221ac58cfc2/Screen_Shot_2016-07-20_at_6.43.15_AM.png)


See merge request !5362

API for downloading latest successful build

## What does this MR do?

Implement parts of #4255, particularly the API.

## Are there points in the code the reviewer needs to double check?

I still made it that `ref` could be either branch, tag, or even SHA with:

``` ruby
# ref can't be HEAD, can only be branch/tag name or SHA
scope :latest_successful_for, ->(ref) do
  table = quoted_table_name
  # TODO: Use `where(ref: ref).or(sha: ref)` in Rails 5
  where("#{table}.ref = ? OR #{table}.sha = ?", ref, ref).
    success.order(id: :desc)
end
```

Because the reasons I put in:

* https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/5142#note_13165543
* https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/5142#note_13165921

But if you still think that it's not good to do it this way, I'll drop it and let's think about the other way to satisfy the requirement specified in https://gitlab.com/gitlab-org/gitlab-ce/issues/4255#note_13101233 It could be `status=any` or `sha=DEADBEAF`

## What are the relevant issue numbers?

Part of #4255

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [x] API support added
- Tests
  - [x] Added for this feature/bug
  - [ ] All builds are passing
- [ ] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [ ] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5347

Prevent toggling sidebar when clipboard icon clicked.

Prevents sidebar being toggle when copy to clipboard icon clicked.

Fixes #19399 

![sidebar-toggle](/uploads/e4e8dfe9ff2546464269242b5f3e34b1/sidebar-toggle.gif)

See merge request !5326

Fix side by side comment widget

Fixes comment button for empty lines in side by side diff view.

Fixes #19824 
Fixes #19957

See merge request !5262

Added the ability to block sign ups using a domain blacklist.

As part of this MR, I restructured the Application Settings form to separate **Sign up** related settings from **Sign in** related settings and make everything cleaner and easier to read.

Fixes #19749 

Related to #5573

See merge request !5259

Add support for inline videos in issue, MR and notes (on issue, commit, MR, and MR diff)

## What does this MR do?

It adds support for inline videos in issue, MR and notes (on issue, commit, MR, and MR diff). Most of the work was done by @hayesr in !3508 but a few improvements were still missing.

## Why was this MR needed?

To be able to play uploaded videos in GitLab!

## What are the relevant issue numbers?

Closes #4142.

## Screenshots

### Video players

![Screen_Shot_2016-07-19_at_18.44.09](/uploads/e85e531b455a41c3e66b26b356abaafd/Screen_Shot_2016-07-19_at_18.44.09.png)

-----

![Screen_Shot_2016-07-19_at_18.44.29](/uploads/05f52a812760210d1eae86a7f8fc48bc/Screen_Shot_2016-07-19_at_18.44.29.png)

-----

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- Tests
  - [x] Test `VideoLinkFilter`
  - [x] Test in `spec/features/markdown_spec.rb`
  - [x] Improve `spec/uploaders/file_uploader_spec.rb`
  - [x] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5215

Add link to profile to commit avatar

## What does this MR do?

- links to user profiles to the avatars on commits page
- tooltips to the avatars on commits page

side effect:

- links to user profiles to the avatars on pipelines page
- tooltips to the avatars on pipelines page
- tooltips to the avatars on activity page
- mailto links to the avatars on activity page for non-registered users

## Are there points in the code the reviewer needs to double check?

Nope.

## Why was this MR needed?

There were no links nor Zeldas.

## What are the relevant issue numbers?

fixes #19644 


See merge request !5163

Allow slack service to send messages on different channels

closes #8110 

## Allow slack service to send messages on different channels  

![new_slack_service](/uploads/87de0bd6b02a4f7853358676b5e74dff/new_slack_service.png)

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [x] API support added
- Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5124

Resolve "Move Build badges settings to Builds page (or Builds settings)"

## What does this MR do?
Removes pipeline settings section from project settings & creates a new pipelines settings page    
Adds builds badge to pipelines settings page & removes badge page

## Are there points in the code the reviewer needs to double check?
All Rails updates -> particularly `builds_controller.rb` and `routes`   
Spacing needs to be updated across all settings pages and will be in a separate MR (https://gitlab.com/gitlab-org/gitlab-ce/issues/19827)

## What are the relevant issue numbers?
Closes #15343    
Part of #18920 

## Screenshots (if relevant)
![Screen_Shot_2016-07-19_at_5.47.29_AM](/uploads/48e6d203de4cbe0b697280128695d980/Screen_Shot_2016-07-19_at_5.47.29_AM.png)
![Screen_Shot_2016-07-14_at_9.25.13_AM](/uploads/59118440f3e7bb903f44260abb119376/Screen_Shot_2016-07-14_at_9.25.13_AM.png)

See merge request !5244

Fix Issue 19641 (new snippets style bug)

## What does this MR do?
Fixes Issue 19641 (new snippets style bug)

## Are there points in the code the reviewer needs to double check?
Shouldn't be

## Why was this MR needed?
Requested in issue 19641 by Fatih Acet https://gitlab.com/gitlab-org/gitlab-ce/issues/19641

## What are the relevant issue numbers?
19641

## Screenshots (if relevant)
![Screenshot_2016-07-09_13.25.39](/uploads/8ead7ea8f4aae7ccaa4d2ddc495b6fe3/Screenshot_2016-07-09_13.25.39.png)
## Does this MR meet the acceptance criteria?
Yes

- [ x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ NA] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ NA] API support added
- Tests
  - [NA ] Added for this feature/bug
  - [ X] All builds are passing
- [X ] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x ] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [ x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5170

Allow to disable user request access to groups/projects

fixes #18585 

![projects](/uploads/9f381e77ffbcd2ecdbabdb8b201b95e4/projects.png)  

![namespaces](/uploads/4b8d39c80576b499118373f0a221882c/namespaces.png)

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5286

Log cron_jobs configuration instead of raising exception

## What does this MR do?

Log cron_jobs configuration errors and remove invalid key <-> values from the configuration hash instead of raising an exception.
This has been discussed at #20010.

Fixes #20010

## Are there points in the code the reviewer needs to double check?

## Why was this MR needed?

Original implementation !5318, introduced a regression with our docker packaging: #20010.

## What are the relevant issue numbers?

* #20010 
* #18378

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- Tests
  - [ ] Added for this feature/bug
  - [ ] All builds are passing
- [ ] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [ ] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5360

Merge branch '20003-newnoteworker-failing-repeatedly-with-argumenterror-wrong-number-of-arguments' into 'master'

Ensure to_json methods take optional argument

If only Ruby had static checking for interfaces like this 😀 

Closes #20003.

See merge request !5359

Fix migration corrupting import data for old version upgrades

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/19073

Not a fan of changing old migrations but this will prevent issues from upgrading GitLab version 8.6 or older to 8.10

More details of the issue on https://gitlab.com/gitlab-org/gitlab-ce/issues/19073#note_13190450

See merge request !5358

Expire tags/branches repo cache before delete a repository

## What does this MR do?

Explicitly expire tag and branch cache data before deleting a repository. Those keys don't depend on git data when they are expired

## Why was this MR needed?

To solve an existing problem https://sentry.gitlap.com/gitlab/gitlabcom/issues/8756/

## What are the relevant issue numbers?

Closes #20011

## Screenshots (if relevant)

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- ~~[ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)~~
- ~~[ ] API support added~~
- Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5356

Fix the Sentry spam from CSP violations by disabling it.

## What does this MR do?

Leaves CSP enabled, but without a reporting endpoint for now. This was causing a huge amount of useless errors in our Sentry instance.

cc: @stanhu 

See merge request !5354

Ensure Owners are included in the scope for authorized_projects

Prior, when providing a `min_access_level` parameter to this method, we
called `Gitlab::Access.values` instead of `all_values`, mistakenly
omitting the `OWNER` level.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/19878

See merge request !5353

upgrade rouge to 2.0.5

## What does this MR do?
Upgrades Rouge to 2.0.5

## Are there points in the code the reviewer needs to double check?
No

## Why was this MR needed?
New lexers and bugfixes from upstream.

## What are the relevant issue numbers?

## Screenshots (if relevant)

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- Tests
  - [ ] Added for this feature/bug
  - [ ] All builds are passing
- [ ] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [ ] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5351

Fix help page paths to make sure shortcuts and the UI help page work.

Add a test to make sure the help page UI path doesn't break in the future.

Fixes #19972 and #19889.

cc: @dzaporozhets @rspeicher @lbennett 

See merge request !5350

Fix styling of tag page

## What does this MR do?
Fixes tag page UI

## Screenshots (if relevant)
Before:    
![Screen_Shot_2016-07-18_at_3.09.28_PM](/uploads/575776fe7917321307baf2b8c2b34d75/Screen_Shot_2016-07-18_at_3.09.28_PM.png)
After:    
![Screen_Shot_2016-07-18_at_3.09.08_PM](/uploads/44f905318c01eb094989cb74bcd4c3c1/Screen_Shot_2016-07-18_at_3.09.08_PM.png)

See merge request !5334

Fixed GFM autocomplete not loading on wiki pages

## What does this MR do?

Allows the GFM autocomplete to work on wiki pages.

## What are the relevant issue numbers?

Closes #19580 

See merge request !5132

Implements the form for renaming the new filename on the file edit page

## What does this MR do?
Adds the possibility to edit a filename when editing the content of a file on Gitlab

this MR was made to solve #5850 

![Screen_Shot_2016-07-01_at_16.45.53](/uploads/eeed05800e3dc11f1e3840e0e4fa06b5/Screen_Shot_2016-07-01_at_16.45.53.png)

See merge request !5049

Updated fork page UI

## What does this MR do?

Updates fork page to new UI.

## Are there points in the code the reviewer needs to double check?

😕 

## Why was this MR needed?

'coz new forks page looks awesome, that's why!

## What are the relevant issue numbers?

Closes #17810.

## Screenshots (if relevant)

![Screen_Shot_2016-07-07_at_03.43.45](/uploads/d4be046d1a6b043f3691633b7ec396c6/Screen_Shot_2016-07-07_at_03.43.45.png)

[youtube video](https://youtu.be/YpXPCxWGCnY)

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- Tests
  - [ ] Added for this feature/bug
  - [ ] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5007

Add predefined CI variables to GitLab

## What does this MR do?
This adds predefined CI variables to GitLab for container registry, pipelines, project name, etc. It also makes sure that all currently documented variables are send from GitLab. This is added to follow up on this proposal: https://gitlab.com/gitlab-org/gitlab-ci-multi-runner/issues/185#note_11844286. To migrate almost all variables out of Runner to GitLab to simplify adding a new of variables without the need for changing the GitLab Runner.

## Why was this MR needed?
Our CI variables miss a lot of crucial information that should be easily accessible. This tries to fill this gap.

## What are the relevant issue numbers?
Fixes https://gitlab.com/gitlab-org/gitlab-ci-multi-runner/issues/185, https://gitlab.com/gitlab-org/gitlab-ce/issues/18164, https://gitlab.com/gitlab-org/gitlab-ce/issues/18075.

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- Tests
  - [ ] Added for this feature/bug
  - [ ] All builds are passing
- [ ] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [ ] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)


See merge request !4826