Fix timing problems running imports on production

Fixes https://gitlab.com/gitlab-com/infrastructure/issues/151

I've found out that in staging, the imported file is not copied fully by the time sidekiq runs the job, this should hopefully fix it. (Tested against staging).

See merge request !5523

Fix attr reader to force the intended values for source and target shas

## What does this MR do?

When importing a pull request from GitHub, the old and new branches may no longer actually exist by those names, but we need to recreate the merge
request diff with the right source and target shas.  We use these `target_branch_sha` and `source_branch_sha` attributes to force  these to the intended values. But the reader methods were always looking up to the target/source branch head instead of check if these values was  previously set, this MR applies a memoization pattern to both of them.

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

This [commit](https://gitlab.com/gitlab-org/gitlab-ce/commit/6ce25e7b4caa9e94de74378729178c7060d640b2) introduced this bug in the importer.

## What are the relevant issue numbers?

gitlab-org/gitlab-ce#20385

## 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
  - [ ] All builds are passing
- [x] 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 @akitaonrails @DouweM 

See merge request !5573

Gitlab::Metrics.current_transaction needs to be public for RailsQueueDuration

See merge request !5592

Changed grant_type=AUTHORIZATION_CODE for grant_type=authorization_code

## What does this MR do?

Changed grant_type=AUTHORIZATION_CODE for grant_type=authorization_code 

## Why was this MR needed?
Using the example when provided the parameter grant_type=AUTHORIZATION_CODE the server returns a error:
```json 
{"error":"unsupported_grant_type","error_description":"The authorization grant type is not supported by the authorization server."}
```


See merge request !5539

Trim extra displayed carriage returns in diffs and files with CRLFs

## What does this MR do?

This MR strips out extra carriage returns at the end of each tokenized string.

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

Does this remove more than we need?

## Why was this MR needed?

Windows users would see extra lines in their files. Newline characters are already added with every line in the HTML formatter.

## What are the relevant issue numbers?

#20440, gitlab-com/support-forum#892, #20468 

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- 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 !5588

Avoid line_code and position calculation on line partial for plain view

See merge request !5591

Sensible state specific default sort order for issues and merge requests

## What does this MR do?

It provides more sensible default sort order for issues and merge requests based on the following table:

    | type           | state  | default sort order |
    |----------------|--------|--------------------|
    | issues         | open   | last created       |
    | issues         | closed | last updated       |
    | issues         | all    | last created       |
    | merge requests | open   | last created       |
    | merge requests | merged | last updated       |
    | merge requests | closed | last updated       |
    | merge requests | all    | last created       |

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

All the bits where `id_desc` was changed to `created_desc`.
 
I hope it's okay, It makes more sense in my opinion.

## Why was this MR needed?

Prior to this MR the issues and merge request were sorted based on `id_desc` by default. 

This MR aims to make the interface more user-friendly by providing state specific sorting defaults most users would expect. 

## What are the relevant issue numbers?

See #15064 

See merge request !5453

Signed-off-by: Rémy Coutable <remy@rymai.me>

Closes #20440

Fix Importing labels and milestones associations - Import/Export

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/19510 and https://gitlab.com/gitlab-org/gitlab-ce/issues/19447
- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry 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 !5426

Provide more sensible default sort order for issues and merge requests
based on the following table:

| type           | state  | default sort order |
|----------------|--------|--------------------|
| issues         | open   | last created       |
| issues         | closed | last updated       |
| issues         | all    | last created       |
| merge requests | open   | last created       |
| merge requests | merged | last updated       |
| merge requests | closed | last updated       |
| merge requests | all    | last created       |

Add an URL field to Enviroments

## What does this MR do?

Adds a field to the `enviroments` table to expose later in other features. Now I see the task list below, I noticed I forgot some minor things, but Ill adress those after the first review. 

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

The field is a string on the database, thus limited to 255 chars, which seems more than enough.

## What are the relevant issue numbers?

Closes #19527

## Screenshots (if relevant)

![Screen_Shot_2016-07-25_at_15.22.16](/uploads/5c3f39466f8e2114195270006aed20c0/Screen_Shot_2016-07-25_at_15.22.16.png)![Screen_Shot_2016-07-25_at_15.22.53](/uploads/408cf86610137dd4a861d15dcd677a2c/Screen_Shot_2016-07-25_at_15.22.53.png)![Screen_Shot_2016-07-25_at_15.23.10](/uploads/927c506931f4e0338cdbbc58678bd308/Screen_Shot_2016-07-25_at_15.23.10.png)

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [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] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5469

Make "New issue" button in Issue page less obtrusive

## What does this MR do?

Replace green background of "New issue" button on issue page by green border and text.

## Why was this MR needed?

Every issue page has two green buttons—Comment and New Issue.

- New Issue is not directly content related and less likely to be used.
- [UI Guide] says

> Use green or blue button for primary action. Primary button should be only one.

[UI Guide]: https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/ui_guide.md

## What are the relevant issue numbers?

fixes #20186

## Screenshots

### Before

![before](/uploads/53ab065edb87b3e3c2f25d828b2fcc42/before.png)

### After

![after](/uploads/a9b4254d563a93098fa2f1cecb78f96f/after.png)


See merge request !5457

Clarify CI script needing to quote colons

## What does this MR do?

Clarifies documentation for `.gitlab-ci.yml` `script`.

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

Should this be a note? Is there a link to YAML spec we can point to?

## Why was this MR needed?

## What are the relevant issue numbers?

Closes #20177.

## Screenshots (if relevant)


See merge request !5481

squashed - fixed label and milestone association problems, updated specs and refactored reader class a bit

added changelog

fix specs

refactored code based on feedback

fix rubocop warning

Update start-using-git.md to reflect that merges to master can be made from either the master or the named branch.

## What does this MR do?

The documentation is incorrect in stating that you need to be in the named branch in order to merge to master.  You can be in master and merge the named branch, too.

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

Yes

## Why was this MR needed?

This MR is needed to correct an inaccuracy in the documentation.

## What are the relevant issue numbers?

N/A

## Screenshots (if relevant)

N/A

## Does this MR meet the acceptance criteria?

It is only a documentation change, so mostly this is not applicable.

- [ ] [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 !5404

Clarify backup_keep_time config parameter with S3

Discussed in gitlab-org/omnibus-gitlab#1453

See merge request !5567

Improve spinach test to be more specific about link to click

If you add another branch to gitlab-test that includes the word 'test', browse_files.feature will fail with an ambiguous match.

See merge request !5589

If you add another branch to gitlab-test that includes the word 'test',
browse_files.feature will fail with an ambiguous match.

Ignore invalid IPs in X-Forwarded-For when trusted proxies are configured.

## What does this MR do?

Catches IPAddr::InvalidAddressError exceptions in `trusted_proxy?` when a) a trusted proxy is set up in the gitlab config and b) an invalid IP address is passed to the method (e.g. one with a port attached). When caught, returns `false` from the method. Prevents a 500 error in this situation.

## What are the relevant issue numbers?

Closes gitlab-org/gitlab-ce#20466.

## Does this MR meet the acceptance criteria?

- [X] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [N/A] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [N/A] 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 !5584

When importing a pull request from GitHub, the old and new branches may
no longer actually exist by those names, but we need to recreate the
merge request diff with the right source and target shas.

We use these `target_branch_sha` and `source_branch_sha` attributes to
force these to the intended values. But the reader methods were always
looking up to the target/source branch head instead of check if these
values was previously set.

Clarify which project is deleted to avoid alarm

Some users were alarmed when navigating after deleting  a project. Add the project name to avoid cause for alarm.

Closes #13654 

See merge request !5574

Properly abort a merge when merge conflicts occur

If somehow a user attempted to accept a merge request that had conflicts (e.g. the "Accept Merge Request" button or the MR itself was not updated), `MergeService` did not properly detect that a conflict
occurred. It would assume that the MR went through without any issues and close the MR as though everything was fine. This could cause data loss if the source branch were removed.

Closes #20425

See merge request !5569

Improve diff performance by eliminating redundant checks for text blobs

See merge request !5575

On a merge request with over 1000 changed files, there were redundant
calls to blob_text_viewable?, which incurred about 7% of the time.

Improves #14775

Closes #13654

Also a couple of minor edits for this branch are included