Add back check if we're losing commits in a merge.

git operation inside GitHooksService. Feedback:

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/7237#note_19210942

TODO: Fix tests for update_branch_with_hooks

* upstream/master: (288 commits)
  Added a changelog entry
  WIP: Adds a default commit message when adding a README (#25167)
  Change prop name to keep consistency with other props.
  Adds changelog entry
  Change ref property to commitRef
  Test all values for `enabled_git_access_protocol`
  Fixes ActionView::Template::Error: undefined method `text?` for nil:NilClass
  Simplify `branch_name` in bin/changelog
  Speed up project snippet security request specs
  Remove change to MWBS in code review guideline
  Enable ColorVariable in scss-lint
  Clean up common_utils.js (!7318)
  24726 Remove Across GitLab from side navigation
  Remove source sans pro
  Use system font
  Update CHANGELOG.md for 8.14.2
  Don't allow to specify a repo or version when installing Workhorse
  Fixed row margins on Pipeline Settings page in order to unify styles
  Fix URL rewritting in the Help section
  Allow public access to some Project API endpoints
  ...

If SSH prototol is disabled don't say the user requires SSH keys

Closes #24921

See merge request !7840

Use system font

Just for fun....   
### macOS Chrome (San Francisco):   
![Screen_Shot_2016-11-17_at_4.01.29_PM](/uploads/bfbab440ea0136314a6a7cffcd44f3ff/Screen_Shot_2016-11-17_at_4.01.29_PM.png)
### macOS Safari (San Francisco):   
![Screen_Shot_2016-11-18_at_8.28.22_AM](/uploads/3adc05d7adf84ca726cbaaf36cb0567d/Screen_Shot_2016-11-18_at_8.28.22_AM.png)
#### Ubuntu Firefox (Ubuntu): 
![Screen_Shot_2016-11-18_at_8.31.08_AM](/uploads/0f0d581d2d79d5db3dba9b2200499dc7/Screen_Shot_2016-11-18_at_8.31.08_AM.png)
#### Windows 7 IE 11 (Segoe UI): 
![Screen_Shot_2016-11-18_at_8.35.05_AM](/uploads/88efc2c554252de03fb84cc3c3e2856e/Screen_Shot_2016-11-18_at_8.35.05_AM.png)

See merge request !7545

Adds a default commit message when adding a README (#25167)

Closes #25167

See merge request !7903

Change ref property to commitRef

## What does this MR do?
Changes `ref` prop to `commitRef` because `ref` is a reserved word in Vue.js

## Does this MR meet the acceptance criteria?

- [x] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) 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 [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [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 it does - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?
Closes #25264

//cc @selfup

See merge request !7901

Clean up common_utils.js

## What does this MR do?

- Remove unused functions from `common_utils.js`.
- Move functions which are used from only one file to that file.

## Why was this MR needed?

Because some utils weren't that common (anymore).

See merge request !7318

Fixes ActionView::Template::Error: undefined method `text?` for nil:NilClass

Closes #25251

See merge request !7893

Enable ColorVariable in scss-lint

## What does this MR do?

- Enable the ColorVariable rule in`.scss-lint.yml`
- Change all color literals in `app/assets/stylesheets` to color variables

## Why was this MR needed?

- Enforce the usage of color variables to better constrain the various color values being used

## Does this MR meet the acceptance criteria?

- [x] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- Tests
  - [x] All builds are passing
- [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [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 it does - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?


Closes #23500

See merge request !7319

Fixed row margins on Pipeline Settings page in order to unify styles

On the ```project-name/pipelines/settings``` page, I removed the ```.row``` styling on ```.build-status``` and ```.coverage-report``` as it was causing those rows to not have the same margins as the "CI/CD Pipeline" row.

Now, they are even as you can see below:

![Screen_Shot_2016-12-01_at_12_54_59_PM](/uploads/a7196ff2e8efcdcd072bc2d26634a42d/Screen_Shot_2016-12-01_at_12_54_59_PM.png)

![Screen_Shot_2016-12-01_at_12_53_18_PM](/uploads/615428bab476fcd1baab86837395d800/Screen_Shot_2016-12-01_at_12_53_18_PM.png)

Closes #25098 
cc: @filipa

See merge request !7881

Simplify `branch_name` in bin/changelog

The `--short` option has existed since at least 1.8.1:
https://git-scm.com/docs/git-symbolic-ref/1.8.1

See merge request !7891

Speed up project snippet security request specs

Part of https://gitlab.com/gitlab-org/gitlab-ce/issues/24899

See https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/7779 and
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/7813

See merge request !7890

Use gitlab-workhorse 1.1.0. Adds Prometheus support and more.

See merge request !7868

The `--short` option has existed since at least 1.8.1:
https://git-scm.com/docs/git-symbolic-ref/1.8.1

Part of https://gitlab.com/gitlab-org/gitlab-ce/issues/24899

See https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/7779 and
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/7813

Update  API spec files to describe the correct class by changing `API::API` to the corresponding class, for example `API::AwardEmoji`.

Closes #24902

See merge request !7718

Extend code review docs with chapter about the right balance

[ci skip]

See merge request !7838

[ci skip]

Don't allow to specify a repo or version when installing Workhorse

I've also updated the "patch version upgrade" doc since I did forget to update it in !6574.

See merge request !7879

Pass commit data to ProcessCommitWorker

This changes `ProcessCommitWorker` so that it takes a Hash containing commit data instead of a commit SHA. This means the worker doesn't have to access Git just to process a commit message (and other data it may use). This in turn should solve the problem of ending up with 15 000-something jobs in the `process_commit` queue that take forever to process.

See merge request !7744

Allow public access to some Project API endpoints

## What does this MR do?

This opens up a few endpoints in the Project API:

- `GET /projects/visible` (returns public projects only)
- `GET /projects/search/:query` (returns results only for public projects)
- `GET /projects/:id` (only if the project is public)
- `GET /projects/:id/events` (only if the project is public)
- `GET /projects/:id/users` (only if the project is public)

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

I've chosen to explicitly add `authenticate!` to GET methods that still need a current user.

## Does this MR meet the acceptance criteria?

- [x] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) 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

Part of #4269

See merge request !7843

Replace static fixture for notes_spec

## What does this MR do?

Replace `comments.html.haml` and `issue_note.html.haml` used in `notes_spec.js` by dynamically created fixture.

## What are the relevant issue numbers?

#24753

See merge request !7683

24726 Remove Across GitLab from side navigation

## What does this MR do?

Removes Across GitLab header from side navigation

## Screenshots (if relevant)
Before:
![Screen_Shot_2016-12-01_at_11.09.12_AM](/uploads/7a8c32a1736a55e0baedf071c21e98db/Screen_Shot_2016-12-01_at_11.09.12_AM.png)

After:
![Screen_Shot_2016-12-01_at_11.09.02_AM](/uploads/4d095ec6e4e756abf0301678bb40d59b/Screen_Shot_2016-12-01_at_11.09.02_AM.png)

## Does this MR meet the acceptance criteria?

- [ ] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) 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 [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [ ] 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 it does - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?


Closes #24726

See merge request !7883

Pipelines tabs

## What does this MR do?
Changes the URL when the builds tab is clicked making it possible to be shared.

1. Adds a standard way to handle linked tabs:
    *   This behaviour is already present in the merge requests, commit and user `show` page. 
    *    This MR introduces a reusable way to accomplish this behaviour for pages with static content.

2. Adds test:
    *   For the linked tabs reusable class
    *  For the pipelines tabs

## Why was this MR needed?
To allow having a sharable URL that represented the opened tab

![tabs](/uploads/91e663c12c6e9ac46a17aa3a9489dc72/tabs.gif)

## Does this MR meet the acceptance criteria?
- [x] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) 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 [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [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 it does - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?
Closes #24814

See merge request !7709

Replace static fixture for right_sidebar_spec

## What does this MR do?

Replace `right_sidebar.html.haml` for `right_sidebar_spec.js` by already existing dynamically generated fixture.

## What are the relevant issue numbers?

#24753

See merge request !7687

Resolve "User-generated permalink IDs collide with GitLab interface"

## What does this MR do?

Prevents ID values automatically generated by headers in [GitLab Flavored Markdown](https://github.com/gitlabhq/gitlabhq/blob/master/doc/user/markdown.md#header-ids-and-links) from colliding with IDs used elsewhere in the GitLab interface.  This can cause confusion when, for instance, a selector looks for a merge request tab with `id="pipelines"` and there is a header with the same ID earlier in the DOM.

How this works:
* All header IDs generated with GitLab Flavored Markdown are namespaced with `id="user-content_foo"`
* All anchor links which point to these IDs continue to use the non-namespaced hash `<a href="#foo">...</a>`
* When a page is loaded or when the `hashchange` event is triggered, javascript will automatically search for `#user-content_foo` if `#foo` cannot be found, and scroll to that position instead.

## Before

![2016-11-21-13.00.28](/uploads/e3be2cd6a9142dfd6e64db5462a6aa76/2016-11-21-13.00.28.gif)

## After:

![2016-11-21-13.12.45](/uploads/f7ae3f3a30c91325eaa3665591b6a850/2016-11-21-13.12.45.gif)  
![2016-11-21-13.03.00](/uploads/3a6a782c081ecaa05b8781548d794909/2016-11-21-13.03.00.gif)  

## Does this MR meet the acceptance criteria?

- [x] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) added
- Tests
  - [x] Added for this feature/bug
  - [ ] All builds are passing
- [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [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 it does - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?

Closes #22781 

See also prior attempts to address this issue:
#3908, !2023, !2024


See merge request !7631