Refs dropdown is now loaded async

## What does this MR do?

The refs dropdown is loaded async so not to block the page.

## What are the relevant issue numbers?

Part of #18202

## Screenshots (if relevant)

![Screen_Shot_2016-06-07_at_14.41.21](/uploads/8fea12655f96fe7f7008a32677bff037/Screen_Shot_2016-06-07_at_14.41.21.png)

See merge request !4508

Document access request to project & group

## What does this MR do?

Adds documentation that was missing from !3798.

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

I've taken the opportunity to update the images in the "Project users" documentation page, I can remove the commit if it's not welcome!

## What are the relevant issue numbers?

Closes #18584.

## Does this MR meet the acceptance criteria?

- [ ] Tests
  - [ ] 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)

/cc @DouweM 

See merge request !4685

Fallback to group's owners/masters when a project has none for the "access requested email"

## What does this MR do?

From b31c5052:

    Fallback to group's owners/masters when a project has none
    
    A project in a group can have no explicit owners/masters,
    in that case we fallbacks to the group's owners/masters.

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

No.

## Why was this MR needed?

Because of #18757.

## What are the relevant issue numbers?

Fixes #18757.

## Does this MR meet the acceptance criteria?

- [x] No need for CHANGELOG.
- [x] No need for documentation.
- [x] No API support added.
- [x] 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 !4791

POC: Markdown shortcut buttons

## What does this MR do?
Adds markdown shortcut buttons to text area for comments. 

## Are there points in the code the reviewer needs to double check?
Because changing `textarea.val('something')` kills the natural browser undo stack, I had to implement a custom undo stack using state. You can't use the "undoable" state undo pattern because you need to go back to a previous state regardless of cursor position. The undo also adds an undo history item once you delete stuff or press enter.

You can also edit multiple textareas at once and it will keep an undo history for each textarea individually, so the undo state should not collide between textareas.

## Why was this MR needed?
It has been requested multiple times and the competition has it. https://gitlab.com/gitlab-org/gitlab-ce/issues/17185#note_12073433

Libraries are available that already implement this functionality but they are enormous and bloaty. I implemented this in very few lines of code and kept it very simple and as minimal as possible. This was also some competitions approach. I believe so as to not include too much JS. 

Adding extra buttons with new functionality **should only need new HTML and no new JS**.

Only extra complex thing was adding a overridden undo stack, which was made as simple as possible as well.

## What are the relevant issue numbers?
https://gitlab.com/gitlab-org/gitlab-ce/issues/17185#note_12073433

## Screenshots (if relevant)

**NOTE:** One thing you cannot see in this screenshot is that I am pressing <kbd>Cmd</kbd><kbd>Z</kbd> to undo and <kbd>Cmd</kbd><kbd>Shift</kbd><kbd>Z</kbd> to redo which is the undo/redo stack I implemented. <kbd>Ctrl</kbd><kbd>Y</kbd> also works for redo. 
![markdown-editor](/uploads/2517bfb1a7b4269da7fcc4003c88b7f6/markdown-editor.gif)

cc @dzaporozhets for UI

cc @iamphill @alfredo1 for JS review

cc @JobV if you like the idea.

Fixes: #17185

See merge request !4305

Set missing stages on ci builds to 'test' to avoid regressions in the pipelines view

## What does this MR do?

Sets a default stage on old `ci_builds`.

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

Is the migration acceptable for online execution?

## Why was this MR needed?

Old `ci_builds`with no stages cause a regression on the pipelines index view.

## What are the relevant issue numbers?

#17949 

Blocked by https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4680


See merge request !4381

Broken instructions. git fetch --all --tags doesn't refresh tags



See merge request !4092

Add notification_settings:events to schema

See merge request !4800

Fixed placement of close button on merge requests

## What does this MR do?

Fixes the order in which the MR buttons appear

## Screenshots (if relevant)

![Screen_Shot_2016-06-18_at_21.41.38](/uploads/66a88ebc287b7c21160af193ee9de54c/Screen_Shot_2016-06-18_at_21.41.38.png)

![Screen_Shot_2016-06-18_at_21.41.44](/uploads/ba8f6776d79f4eb0af7877c3c71fbb54/Screen_Shot_2016-06-18_at_21.41.44.png)


See merge request !4778

Fix double query string in url

This MR should fix the double query string in url  that shows up while using the "filter by name .."  input  on projects list pages and also closes [17743](https://gitlab.com/gitlab-org/gitlab-ce/issues/17743)

Closes #17743

See merge request !4480

Set path for pinned nav cookie

## What does this MR do?

Sets a path for the pinned nav cookie so it will be present across page reload.

Closes #18836 

See merge request !4784

Document environments and deployments

## What does this MR do?

Adds an introduction to environments and deployments and tweaks the `environments` entry in `.gitlab-ci.yml` documentation.

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

## Why was this MR needed?

## What are the relevant issue numbers?

Closes #18683.

## Screenshots (if relevant)

![image](/uploads/1e3355c543abaf7b358f3c37596b1f0b/image.png)

![image](/uploads/58a51505674bcf605039db46833a8ae6/image.png)

/cc @ayufan @axil 

See merge request !4725

Remove Duplicated keys adding UNIQUE index to fingerprint

See merge request !4787

Avoid autoload issue such as 'Mail::Parsers::AddressStruct'

This is mostly a shot in the dark but at least it shouldn't break anything.

Fixes #18810.

See merge request !4793

Limit push email diff size

Restrict the size of diffs in push emails to 30 lines / 150 KB (whichever is smaller),
following https://gitlab.com/gitlab-org/gitlab_git/merge_requests/85.

Emails on push can get very large if they contain a lot of files that sneak under the single-file limit.

https://gitlab.com/gitlab-org/gitlab-ee/issues/490

See merge request !4566

Move part of admin area navigation from tabs into settings dropdown

Partly fix https://gitlab.com/gitlab-org/gitlab-ce/issues/18799 

See merge request !4796

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Grammar tweaks

## What does this MR do?

* Updates grammar in recent CI documentation.

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

## Why was this MR needed?

Because grammar.

## What are the relevant issue numbers?

Needed because of !4200 and !4201.

## Screenshots (if relevant)


See merge request !4772

Add documentation styleguide  on configuration settings

See merge request !4794

[ci skip]

By eager-loading the Mail gem in the Sidekiq initializer.
Signed-off-by: Rémy Coutable <remy@rymai.me>

Added tests to project controller

A project in a group can have no explicit owners/masters,
in that case we fallbacks to the group's owners/masters.
Signed-off-by: Rémy Coutable <remy@rymai.me>

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Fixed a couple of errors on import/export spotted in production

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/18828 and https://gitlab.com/gitlab-org/gitlab-ce/issues/18829

A couple of tiny bugs spotted after deploying in prod

See merge request !4782

Removes un-used method
Fixes other Ruby issues

Fix RangeError exceptions when referring to issues or merge requests outside of max database values

When using #XYZ in Markdown text, if XYZ exceeds the maximum value of a signed 32-bit integer, we get an exception when the Markdown render attempts to run `where(iids: XYZ)`. Introduce a method that will throw out out-of-bounds values.
    
Closes #18777

See merge request !4777