Fixups to "Round-robin repository storage"

## What does this MR do?

* Simplifies a method in application_settings.rb
* Correctly marks a migration as needing downtime
* Documents the requirement for renamed columns to be 

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

Should any of these changes be split out? Ideally we'd get this into the same point release as !7273

## Why was this MR needed?

Post-facto review of !7273

## Screenshots (if relevant)

## Does this MR meet the acceptance criteria?

- [ ] [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] 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?

Related to #24059

/cc @yorickpeterse @rspeicher

See merge request !7287

Add an index for project_id in project_import_data to improve

See merge request !7316

Refactor template selector in issuable form

CE brother of https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/844

See merge request !7249

Use method helper instead of add_template_helper

On my opinion, better to use method `helper` instead of `add_template_helper`.
Maybe there is reason doing it here. could you please explain if yes?
Thanks!

See merge request !7315

Exposes the label priority to the API. Furthermore, it allows the user to modify the priority via the API.

Closes #21269

See merge request !7286

Fix broken link to observatory cli on Frontend Dev Guide

See merge request !7317

performance

We see that many slow queries on GitLab.com are dominated by finding
the project import data for a specific project. Adding an index is
the most straightforward way of fixing this.

Closes #23748

Remove logging to console in diff_comments_store_spec

## What does this MR do?

Remove `console.log` from `diff_comments_store_spec.js.es6`.

See merge request !7306

Split out markdown cache storage into a separate method

See merge request !7277

Correct spelling of Andreesen's name

[ci skip]

See merge request !7293

Move Spinach public snippet feature test to RSpec feature

See #23036

See merge request !7256

Update avatar container name so it doesnt conflict with other image containers

Bug from https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/7206 renders all wiki images circular   
Before:   
![Screen_Shot_2016-11-03_at_9.27.45_AM](/uploads/f49baa4481cec6d6c043087aa1a83d09/Screen_Shot_2016-11-03_at_9.27.45_AM.png)
After:   
![Screen_Shot_2016-11-03_at_9.27.37_AM](/uploads/5b21d1752b5fa5adcabd44b8973fb55d/Screen_Shot_2016-11-03_at_9.27.37_AM.png)

cc @tauriedavis @dzaporozhets 

See merge request !7268

Add test for refs dropdown selection with special chars

## What does this MR do?

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

## Why was this MR needed?

## Screenshots (if relevant)

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG.md) entry 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)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?

See merge request !7175

Update GitLab Workhorse to v1.0.0, improving error handling

This is an update to v1.0.0 - which does not signify any breaking changes, but is merely in accordance with http://semver.org/#how-do-i-know-when-to-release-100

See merge request !7289

Added Element extension with .matches and .closest

## What does this MR do?

This adds `.matches` and `.closest` polyfills that will help when removing/not using jQuery. I added these in another MR which was then refactored to not require these methods, but I thought we might as well not lose the code.

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

## Why was this MR needed?

Help when removing/not using jQuery.

## Screenshots (if relevant)

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry 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?

See merge request !6946

Creates new list from a new label

## What does this MR do?

After creating a new label in the new list dropdown it automatically creates a new list.

## Screenshots (if relevant)

![new-label](/uploads/87940e364dc075ea8cc08d97bc1f1eff/new-label.gif)

## What are the relevant issue numbers?

Closes #23026

See merge request !6744

Add width to caret to rid ourselves of the shift

## What does this MR do?
Removes the shift from diff files.

## Are there points in the code the reviewer needs to double check?
That it doesn't shift.

## Why was this MR needed?
There was a shift in the minimizing of diff files.

## Screenshots (if relevant)
![switcheroo](/uploads/f9734e1d11715e49008e0ca9104d2d4c/switcheroo.gif)

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [x] API support added
- Tests
  - [ ] 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 https://gitlab.com/gitlab-org/gitlab-ce/issues/23424

See merge request !6934

Added various stylistic changes to commit title area

## What does this MR do?

After https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6994 was merged, there were some things left over.

## Are there points in the code the reviewer needs to double check?
Yes, in general the code.

Apart from that I couldn't get the extended commit sha to lign up correctly on smaller screens

## Why was this MR needed?
Some things weren't done yet.

- Commit description and commit sha are now bold like in the original design, and are also both visible on smaller screens
- You can now extend the commit sha on bigger screens and keep it visible truncated on smaller screens.
- options dropdown button now correctly displays on smaller screens (similar to issue/mr view)

## Screenshots (if relevant)
Before:
![image](https://gitlab.com/gitlab-org/gitlab-ce/uploads/716cb902bd20dedc705a8f81f6536736/Screen_Shot_2016-10-19_at_10.20.01_AM.png)

After:
![image](/uploads/2329c9e2c731f0fc850b4864fb216756/image.png)
![image](/uploads/d8afde519fe276c0bce2286e56ea463b/image.png)

not aligned correctly:
![image](/uploads/9006df59a1de3875b2317f14d3d20872/image.png)


## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG.md) entry 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?
!6994

See merge request !7213

Allow to test JIRA service when project does not have repository

closes #23032

See merge request !7162

Fix applying GitHub-imported labels when importing job is interrupted

Closes #24075

See merge request !7245

Show pipeline status from branch and commit than only commit

Closes #23615

See merge request !7034

Updates deckar01-task_list gem to its latest version

See merge request !7185

Signed-off-by: Rémy Coutable <remy@rymai.me>

Add serializer for environments

## What does this MR do?

This will make it possible to create a payload need in https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/7015 for use with Vue.

## Why was this MR needed?

Closes #23886

See merge request !7174

See merge request !7014
Signed-off-by: Rémy Coutable <remy@rymai.me>

Apply `*_params_ce + *_params_ee` pattern to MergeRequestsController

See merge request !7263

Add setting to only allow merge requests to be merged when all discussions are resolved

_Originally opened at !6385 by @rodolfoasantos._

- - -

## What does this MR do?
Based on #20968 this merge request adds setting only to allow merge requests to be merged when all discussions are resolved. 

## Are there points in the code the reviewer needs to double check?
Check if there are other points to add the resolved discussion setting

## Why was this MR needed?
Add the possibility to configure the project to only accept merge request when all discussions are resolved

## Screenshots

![only_allow_merge_if_all_discussions_are_resolved](/uploads/9388db9421da0214590ffab6fb29f985/only_allow_merge_if_all_discussions_are_resolved.png)

![only_allow_merge_if_all_discussions_are_resolved_msg](/uploads/b1bba0c72ad67d3a1b34718baa08526e/only_allow_merge_if_all_discussions_are_resolved_msg.png)

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [x] [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
- [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 you do - 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 #20968

See merge request !7125

Feedback:
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/7034/diffs#note_17868074

https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/changelog.md