Fix broken side-by-side diff view on merge request page

### What does this MR do?

This MR fixes the side-by-side diff that was broken in v7.9.0. The "Inline" and "Side-by-Side" buttons are now always rendered with HTML links instead of changing depending on whether the code diff was requested in JSON format.

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

Is there a better way to fix this? The links in JSON format may be desirable if there were a JavaScript hook to handle the buttons, but as far as I can tell there isn't at the moment.

### Why was this MR needed?

The issue is that the code diffs can be generated either by the JavaScript handler or the regular HTML. With the forcing of JSON request format in 27e75344, the JavaScript handler requests the page in JSON format, which it then uses to render the page. However, this has the unintended side effect of requesting that the "Inline" and "Side-by-Side" buttons have references to a JSON-formatted link.

### What are the relevant issue numbers / [Feature requests](http://feedback.gitlab.com/)?

#1294

See merge request !460

UI improvements

* Fix diff header for discussion
* Remove unused doorkeeper layout
* Nicer well
* Replace alerts with well where alert is not needed

See merge request !458

Closes #1294

Prevent unnecessary doubling of js events on import pages and user calendar

Adding document.ready in Turbolinks make duplicating of events EVERY visit of page.
In example of user calendar it causes N+1 times ajax request every time you visit user page.

cc @vsizov

See merge request !456

Fix code unfold not working on Compare commits page

### What does this MR do?

The code unfold buttons (`...`) don't work when you go to Commits -> Compare mode. This MR fixes that.

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

Check to make sure all the right initializers are run in the `projects:compare:xxx` case. I'm also not sure if there are other cases where a diff is shown but the code unfolding is not activated.

### What are the relevant issue numbers / [Feature requests](http://feedback.gitlab.com/)?

Closes #1274

See merge request !434

Change ordering so that confirm is removed from attrs before attempting to User.build_user

Possible fix gitlab-org/gitlab-ce#1296

See merge request !445

[doc] Groups can be browsable if they contain at least one public project.

See merge request !451

Notification on project moving

Moving of project should respect notification settings

https://dev.gitlab.org/gitlab/gitlabhq/issues/2091

See merge request !452

Prevent doubling AJAX request with each commit visit via Turbolink

Be careful with `document.ready` in views 😃

cc @vsizov @marin

See merge request !454

Faster merge request processing for large repository

Allow HTML tags in user Markdown input

More rubocop styles

See merge request !449

[ci skip]

* Reduces overhead of git checkout

Documentation - Markdown - added missing line-break info

as promised, I updated the Markdown documentation with the line-breaks info

See merge request !186

Fix GitLab shell setup spacing

Respond with full GitAccess error if user has project read access.

Should help with debugging #1236.

cc @marin

See merge request !437

Improve sticky headers in diffs

* disable sticky headers in discussion
* enable sticky header on mr page with you click changes tab

See merge request !450

* disable sticky headers in discussion
* enable sticky header on mr page with you click changes tab

Milestones and labels can be used even when issues are disabled.

When Issues are disabled for a project Milestones and Labels can still be used for Merge Requests.

See merge request !1739

Change merge request button color based on CI status

Green button looks confusing when CI fails

Screenshots:

![ci-warn](https://gitlab.com/gitlab-org/gitlab-ce/uploads/f8166c9acf35f9d886f37f52f975acfb/ci-warn.png)
![ci-can](https://gitlab.com/gitlab-org/gitlab-ce/uploads/d7319c4c567c42a47d79953191384f96/ci-can.png)

See merge request !448

Link note avatar to user.

See merge request !446

Clean up subscriptions when user is deleted.

cc @vsizov

See merge request !439

Update rugments to 1.0.0.beta6 to fix C# highlighting.

Fixes #1259.

See merge request !435