Reduce base font sizes across app by 1px

Looking at other websites that use system fonts, the default seems to be `14px`. We currently use `15px` which feels a little too big at the moment (in my opinion). This is just an idea so feel free to close it @awhildy 😄    
Before:   
![Screen_Shot_2016-12-02_at_1.46.25_PM](/uploads/4e287d3e66b1fe1dbac9999978594546/Screen_Shot_2016-12-02_at_1.46.25_PM.png)
After:   
![Screen_Shot_2016-12-02_at_1.46.02_PM](/uploads/09aed0952c25df214e8e5fb1404d6f4f/Screen_Shot_2016-12-02_at_1.46.02_PM.png)

See merge request !7905

change the date label to match the date used

Closes #1608

See merge request !7860

Bump ruby version to 2.3.3

Part of gitlab-org/gitlab-ce#24629

See merge request !7904

Use the pagination helper in the API

See merge request !7920

Update paranoia from 2.1.4 to 2.2.0.

Working toward #14286.

Includes support for Rails 5.

Changelog: https://github.com/rubysherpas/paranoia/blob/879fd18caa46af70fceca2e8f46886b3eff072ec/CHANGELOG.md#220-2016-10-21

See merge request !7922

Fix compatibility with Internet Explorer 11 for merge requests

## What does this MR do?
This merge request restores the compatibility with Internet Explorer 11.

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

## Why was this MR needed?
Commit ca3c0c6c introduced an incompatibility with Internet Explorer 11. On all merge requests in all projects the 'Changes' tab does not display the changes in IE11 but instead fails with 'Something went wrong on our end'. The reason ist, that this code snipped produces different results on Firefox and Internet Explorer 11:

```
var element = document.createElement('a');
element.href = '/some/absolute/url';
alert(element.pathname);
```

With Internet Explorer 11 the alert will print a relative path, whereas with Firefox the alert will print an absolute path. For GitLab this meant that a wrong AJAX URL was composed which resulted in a 404.

## Screenshots (if relevant)
None.

## 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
  - [ ] 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?
#23977 
#24380

See merge request !7525

Rename MWBS service to Merge When Pipeline Succeeds

## What does this MR do?

This MR renames Merge When Build Succeeds feature to Merge When Pipeline Succeeds, because we recently changed the behavior, see https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6675.

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG.md) entry added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [x] All builds are passing

## What are the relevant issue numbers?

Closes #23354

See merge request !7135

Accept `issue new` as command to create an issue

Checkout commit message: 629eb073c2056d0e4d87aefea83d5d384465bee6

cc @pedroms

See merge request !7787

Now only `/trigger issue create` is a valid command, but our UI shows
Issue new everywhere. The default now will be `/trigger issue new`. The
help message is adjusted to reflect this.

Fixes: gitlab-org/gitlab-ce#25025

Includes support for Rails 5.

Changelog: https://github.com/rubysherpas/paranoia/blob/879fd18caa46af70fceca2e8f46886b3eff072ec/CHANGELOG.md#220-2016-10-21

Fix gfm doc typo about two spaces for next line transfer

Fixes #25148

See merge request !7915

API: Expose committer details for a commit

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/22312

See merge request !7849

Patch upgrade documentation should be consulted on stable branch

Closes #25245.

See merge request !7892

Revert "Merge branch 'docs/patch-guide-link-to-old-guide' into 'master'"

Reverting in favor of https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/7892

See merge request !7911

This reverts merge request !7909

Link to old patch update guide now that we install workhorse with a raketask

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/25284

See merge request !7909

[ci skip]

Resolve "Highlighting lines is broken"

## What does this MR do?

Add line highlighting back to diff view.  This was working in the MR "changes" tab, but not on a commit page such as https://gitlab.com/winniehell/reproduction-area/commit/9101e66f5761929002956e0f2dd65d7f8643903d

~~This MR also fixes the `scrollToElement` method in `MergeRequestTabs` to account for the extra height of the tab links which are now fixed in place once they are scrolled to the top of the screen.~~ (removed in favor of !7051)

This MR also refactors much of the `Diff` and `MergeRequestTabs` classes to es6 syntax in an effort to increase readability.

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

Check out both MR "change" tabs and commit diff pages and ensure that line highlighting works and that loading a page with one of these permalink hashes correctly highlights and scrolls to the line.

Ensure I didn't break anything in the transition to es6 syntax.  Check the functionality of the tabs on MR pages, as well as diff page interactivity (unfolding hidden lines in diff files, adding comments to diffs, etc).  I have checked these myself, but another set of eyes would be a good idea.

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG.md) entry added
- 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 #23696

See merge request !7090

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

Closes #24921

See merge request !7840

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