Improve usability for prioritized labels

## What does this MR do?
- Adds an icon next to prioritized label rows serving as a hint to the user that the labels can be sorted by dragging them.
- Adds description about prioritized labels.
- Restores empty message when removing all prioritized labels.

## Screenshots (if relevant)

![labels](/uploads/1da16c4c54a894fa45ccc47e3a5bdf7a/labels.gif)

Closes #18575 

See merge request !4652

New Project page improvements for mobile

## What does this MR do?

Redesigns the "Project path" fields on the New Project page.

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

Not that I know of, nothing I changed should break any other pages.

## Why was this MR needed?

The new project page was unusable on mobile because the project name text field didn't have enough space.

## What are the relevant issue numbers?

Fixes #18599.

## Screenshots (if relevant)

Before:

![Screen_Shot_2016-06-15_at_12.38.58_PM](/uploads/046a824b283e24266cabc9ea3dfb169c/Screen_Shot_2016-06-15_at_12.38.58_PM.png)

After:

![Screen_Shot_2016-06-15_at_12.37.19_PM](/uploads/6d01310192965b413bfedd9c8d2129f7/Screen_Shot_2016-06-15_at_12.37.19_PM.png)

![Screen_Shot_2016-06-15_at_12.37.28_PM](/uploads/3944a0f0ab04373ec92f7cafe90872df/Screen_Shot_2016-06-15_at_12.37.28_PM.png)

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ ] Tests
  - [x] Added for this feature/bug
  - [ ] All builds are passing
- [x] 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 you do - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

cc: @jschatz1 @dzaporozhets 

See merge request !4687

Pinned sidebar navigation option

## What does this MR do?

Gives the ability to pin the sidebar navigation. Pinning is only possible on screens with above `lg` which is `1200px` if not it reverts to being hidden by default.

## What are the relevant issue numbers?

Closes #18542 

## Screenshots (if relevant)

### Un-pinned

![Screen_Shot_2016-06-15_at_17.29.08](/uploads/82b7495df6ea46a2334a7c25d03b019b/Screen_Shot_2016-06-15_at_17.29.08.png)

### Pinned

![Screen_Shot_2016-06-15_at_17.29.41](/uploads/3eb381be807985d0a9583f000cb802f9/Screen_Shot_2016-06-15_at_17.29.41.png)

See merge request !4683

Update CHANGELOG for 8.8.5 release

[ci skip]

See merge request !4688

Fair usage of Shared Runners

## What does this MR do?

Introduces a fair usage scheduler for shared runners.

It tries to assign builds to shared runner from projects that have the lowest number of builds currently running on shared runners.

**Example 1**:
```
We have following builds in queue:
build 1 for project 1
build 2 for project 1
build 3 for project 1
build 4 for project 2
build 5 for project 2
build 6 for project 3

With the new algorithm we will assign builds in following order:
- We choose build 1, because project 1 doesn't run currently any builds and has the lowest build number from projects that doesn't run builds,
- We choose build 4, because project 2 doesn't run currently any builds and has the lowest build number from projects that doesn't run builds,
- We choose build 6, because project 3 doesn't run currently any builds and has the lowest build number from projects that doesn't run builds,
- We choose build 2, because project 1 as other it runs 1 build,
- We choose build 5, because project 2 runs 1 build, where project 1 runs 2 builds now,
- We choose build 3, because project 1 and runs 2 builds.
```

 
**Example 2**:
```
We have following builds in queue:
build 1 for project 1
build 2 for project 1
build 3 for project 1
build 4 for project 2
build 5 for project 2
build 6 for project 3

With the new algorithm we will assign builds in following order:
- We choose build 1, because project 1 doesn't run currently any builds and has the lowest build number from projects that doesn't run builds,
- We finish build 1,
- We choose build 2, because project 1 doesn't run currently any builds and has the lowest build number from projects that doesn't run builds,
- We choose build 4, because project 2 doesn't run currently any builds and has the lowest build number from projects that doesn't run builds,
- We finish build 4,
- We choose build 5, because project 2 doesn't run currently any builds and has the lowest build number from projects that doesn't run builds,
- We choose build 6, because project 3 doesn't run currently any builds,
- We choose build 3, because project 1, 2 and 3 runs exactly one build now,
```

## Why was this MR needed?

Currently, we are scheduling builds using FIFO. This is catastrophic if there are projects that create a 100-300 jobs, this basically eats most of available shared runners.

## Performance

All this logic is implemented with the help of SQL queries, because this is the fastest way to process 1k-2k pending builds in queue.
It's not the fastest SQL query, because it sorts based on number of running_builds, and this forces to calculate a number of running builds for all dependent projects. However, since we have one/two shared runners that asks every few seconds for builds this should have minimal impact on DB performance.

```
 explain analyze SELECT "ci_builds".* FROM "ci_builds" JOIN (SELECT "ci_builds"."gl_project_id", count(case when status = 'running' AND runner_id = (SELECT "ci_runners"."id" FROM "ci_runners" WHERE "ci_runners"."is_shared" = 't') then 1 end) as running_builds FROM "ci_builds" INNER JOIN "projects" ON "projects"."id" = "ci_builds"."gl_project_id" AND "projects"."pending_delete" = 'f' WHERE "ci_builds"."type" IN ('Ci::Build') AND "ci_builds"."status" IN ('running', 'pending') AND "projects"."builds_enabled" = 't' AND "projects"."shared_runners_enabled" = 't' GROUP BY "ci_builds"."gl_project_id") AS projects ON ci_builds.gl_project_id=projects.gl_project_id WHERE "ci_builds"."type" IN ('Ci::Build') AND "ci_builds"."status" = 'pending' AND "ci_builds"."runner_id" IS NULL  ORDER BY projects.running_builds ASC, ci_builds.id ASC;
                                                                                  QUERY PLAN                                                                        
           
--------------------------------------------------------------------------------------------------------------------------------------------------------------------
-----------
 Sort  (cost=64777.28..64777.29 rows=1 width=1010) (actual time=301.794..302.535 rows=1537 loops=1)
   Sort Key: (count(CASE WHEN (((public.ci_builds.status)::text = 'running'::text) AND (public.ci_builds.runner_id = $0)) THEN 1 ELSE NULL::integer END)), public.ci
_builds.id
   Sort Method: quicksort  Memory: 1423kB
   ->  Nested Loop  (cost=63279.78..64777.27 rows=1 width=1010) (actual time=66.384..298.724 rows=1537 loops=1)
         ->  HashAggregate  (cost=63177.15..63177.30 rows=15 width=15) (actual time=65.641..65.851 rows=187 loops=1)
               InitPlan 1 (returns $0)
                 ->  Seq Scan on ci_runners  (cost=0.00..26963.66 rows=1 width=4) (actual time=1.145..34.381 rows=1 loops=1)
                       Filter: is_shared
                       Rows Removed by Filter: 6965
               ->  Nested Loop  (cost=0.00..36186.34 rows=2715 width=15) (actual time=0.065..29.717 rows=1710 loops=1)
                     ->  Index Scan using index_ci_builds_on_status on ci_builds  (cost=0.00..8913.95 rows=3577 width=15) (actual time=0.051..12.012 rows=2583 loops
=1)
                           Index Cond: ((status)::text = ANY ('{running,pending}'::text[]))
                           Filter: ((type)::text = 'Ci::Build'::text)
                           Rows Removed by Filter: 1219
                     ->  Index Scan using projects_pkey on projects  (cost=0.00..7.61 rows=1 width=4) (actual time=0.003..0.004 rows=1 loops=2583)
                           Index Cond: (id = public.ci_builds.gl_project_id)
                           Filter: ((NOT pending_delete) AND builds_enabled AND shared_runners_enabled)
                           Rows Removed by Filter: 0
         ->  Bitmap Heap Scan on ci_builds  (cost=102.63..106.64 rows=1 width=1002) (actual time=1.216..1.231 rows=8 loops=187)
               Recheck Cond: ((gl_project_id = public.ci_builds.gl_project_id) AND ((status)::text = 'pending'::text))
               Filter: ((runner_id IS NULL) AND ((type)::text = 'Ci::Build'::text))
               ->  BitmapAnd  (cost=102.63..102.63 rows=1 width=0) (actual time=1.201..1.201 rows=0 loops=187)
                     ->  Bitmap Index Scan on index_ci_builds_on_gl_project_id  (cost=0.00..10.52 rows=241 width=0) (actual time=0.406..0.406 rows=1944 loops=187)
                           Index Cond: (gl_project_id = public.ci_builds.gl_project_id)
                     ->  Bitmap Index Scan on index_ci_builds_on_status  (cost=0.00..91.78 rows=3089 width=0) (actual time=0.652..0.652 rows=3362 loops=187)
                           Index Cond: ((status)::text = 'pending'::text)
 Total runtime: 303.832 ms
```

## Specific runners

It doesn't affect the specific runners which still serve builds FIFO.

@stanhu @markpundsack @yorickpeterse What do you think?


See merge request !4634

[ci skip]

Separate the New Project page's "Project path" grouped fields into separate fields.

Fixes #18599.

Changed breakpoint width to 1440px

Merge branch '18131-pressing-merge-when-build-succeeds-at-the-same-exact-time-that-a-build-is-failing-will-merge-the-failed-build' into 'master'

Fix race condition on auto merge

Resolves #18131

See merge request !4443

Set inverse_of for Project/Services relation

## What does this MR do?

This MR adds the `inverse_of:` option to two associations to reduce the number of queries when running code such as ` project.gitlab_issue_tracker_service.project`.

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

No.

## Why was this MR needed?

In !4410 it was revealed code such as the above is used and would run SQL queries when the root object (usually a Project) was already present. By using `inverse_of` Rails can just re-use those Project instances.

## What are the relevant issue numbers?

None.

## 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~~
- [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 !4674

Fixed issue when nav wasn't present

This ensures that code such as this don't run needless SQL queries:

    project.gitlab_issue_tracker_service.project

This also means that if the root `project` eager loads any associations
the Service object will be able to re-use those.

Get rid of Gitlab::ShellEnv

Remove obsolete code we once needed for Grack and satellites.

See merge request !4673

Resolve "Change admin navigation to match new UI"

## What does this MR do?
Moves admin navigation to layout nav to match Project, Groups, and Profile navigation

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

## Why was this MR needed?

## What are the relevant issue numbers?
Closes #18338

## Screenshots (if relevant)
![Screen_Shot_2016-06-14_at_10.26.40_AM](/uploads/f0b8c8b259da16d929be2b36e8eeafb8/Screen_Shot_2016-06-14_at_10.26.40_AM.png)
![Screen_Shot_2016-06-14_at_10.26.44_AM](/uploads/07d9ece2063dfcfec1f0f2647d8ee782/Screen_Shot_2016-06-14_at_10.26.44_AM.png)
## 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 [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [ ] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !4650

Prevent default disabled buttons and links.

## What does this MR do?
Prevents default action for disabled buttons and links. If the element has `.btn` and `.disabled` at the same time, its default action will be prevented.

## Are there points in the code the reviewer needs to double check?
Yes. Is there a better way to do that?

## Why was this MR needed?
Right now we can click disabled links and it cause some troubles like in #18079.

## What are the relevant issue numbers?
Fixes #18079

## Screenshots (if relevant)
![disabled-click](/uploads/48b58ce130f843e530e62632bcc27436/disabled-click.gif)

## Does this MR meet the acceptance criteria?

- [x] [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
- [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 !4658

Closes #18542

Show number of processed MRs in milestone page

closes #14025 

![Screen_Shot_2016-05-02_at_6.20.34_PM](/uploads/9208e58c0e0c77133bd73332ee3b3342/Screen_Shot_2016-05-02_at_6.20.34_PM.png)

See merge request !4006

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

Add index on `requested_at` to the `members` table

See merge request !4679

Fixed issue with MR buttons being in a group

## What does this MR do?

Fixes design issue with the buttons in the merge request widget

## Screenshots (if relevant)

![Screen_Shot_2016-06-09_at_14.13.32](/uploads/44ac4175f5a97a8d7baf97be6eebc684/Screen_Shot_2016-06-09_at_14.13.32.png)


See merge request !4562

Check if the Users table has exactly one user limiting the whole set

## What does this MR do?

Limit the query set so about a full scan for all the rows on the users table (only scan to records)

#18225 

See merge request !4492

Add support for Docker Registry manifest v1

## What does this MR do?

Adds support for Manifest V1 generated by older versions of Docker (before 1.10).

## What are the relevant issue numbers?

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/18609


See merge request !4669

Fixed issue with de-selecting dropdown option in issue sidebar

## What does this MR do?

When de-selecting either an assignee or milestone, we try to send `undefined` which jQuery removes from the request causing a routing error. Instead this MR sends `null` which jQuery still sends and then correctly removes either the milestone or assignee. 

## What are the relevant issue numbers?

Closes #18641 

## Screenshots (if relevant)

![assignee](/uploads/6eaca416fb6e31eabf4c038967160c07/assignee.gif)

## 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 [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [ ] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !4671

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

Update project star/unstar tooltip

## What does this MR do?
Fixes project toggle star button tooltip to show actual tooltip for its state.

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

## Why was this MR needed?
- When you star a project tooltip wasn't changing.
- When you star a project and refresh the page, tooltip was still showing `Star Project`

## What are the relevant issue numbers?
Fixes #18143

## Screenshots (if relevant)

### Before 
![Screen_Shot_2016-06-15_at_15.31.57](/uploads/e005951c23eeed7c2761a0ec1911f3ce/Screen_Shot_2016-06-15_at_15.31.57.png)

### After
![tooltip-change](/uploads/4caec99eac6ffcc7331947fdfdb9e051/tooltip-change.gif)

## Does this MR meet the acceptance criteria?

- [x] [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
- [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 !4672

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