re-apply MR !6285 "Added forceLoad ability to singleFileDiffs, added callback to getContentHTML, added conditional force load if a collapsed diff line anchor is found"

Use url utility to retrieve hash

temporarily revert "Added forceLoad ability to singleFileDiffs, added callback to getContentHTML, added conditional force load if a collapsed diff line anchor is found"

This reverts commit d2ee3808.

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