Fix Error 500 when using closes_issues API with an external issue tracker

Closes #18484

See merge request !4608

Closes #18484

Improvements to offscreen navigation

Improvements on top of https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4579 based on mockups from https://gitlab.com/gitlab-org/gitlab-ce/issues/18417#note_12389766

See merge request !4607

Resolve "Hide Left sidebar paradigm"

## What does this MR do?
Hides the nav bar by default & centers the tanuki logo in the top nav

## Why was this MR needed?
UX

## What are the relevant issue numbers?
Closes #18417 

## Screenshots (if relevant)
![Screen_Shot_2016-06-10_at_12.49.10_PM](/uploads/c281e4c9de1c1bc9af59ebfa8d2bd18b/Screen_Shot_2016-06-10_at_12.49.10_PM.png)
![Screen_Shot_2016-06-10_at_12.49.27_PM](/uploads/635e0a88230105faa5527f6632899ddb/Screen_Shot_2016-06-10_at_12.49.27_PM.png)
<img src="/uploads/3001a9c723037012f1b86cfacfb1225e/Screen_Shot_2016-06-10_at_12.51.41_PM.png" width="500px">

See merge request !4579

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

Fixed search form padding

## What does this MR do?

Corrects the padding of the search form.

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

Ney.

## Why was this MR needed?

UX

## What are the relevant issue numbers?

Closes #18463.

## Screenshots (if relevant)

![Screen_Shot_2016-06-10_at_14.07.32](/uploads/e4d127c66cf7fa3286279367d6e4ea7c/Screen_Shot_2016-06-10_at_14.07.32.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
- [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 !4591

Only create the backup directory if it is local

Closes #12710

See merge request !4551

Closes #12710

Add Project.where_paths_in

In https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4410 I'm working on reducing the SQL queries needed to render Markdown. One reason for the large amount of queries is executing a large number of queries needed to find projects and related data. Basically `Project.find_with_namespace` is called in a loop and then any relations have to be retrieved separately.

By using `Project.where_paths_in` we can work around this by doing something like:

```ruby
project_paths = [...] # populated by some method
projects = Project.where_paths_in(project_paths).includes(:namespace, ...)
```

Ref: https://gitlab.com/gitlab-org/gitlab-ce/issues/18042

See merge request !4535

Changelog fix for search dropdown arrow keys fix

[ci skip]

See merge request !4580

Remove unused MergeRequest#gitlab_merge_status method

Closes #18462.

See merge request !4593

Revert side nav to full width; remove border under nav; remove tooltips on nav links; stop page content shifting with side nav; put project nav in container

Move Labels and Milestones as sub tab to Issues/MR

## What does this MR do?

UI/UX change. Moves project labels and milestone tabs under Issues and Merge request tabs. 

## Why was this MR needed?

To solve problem of having to many tabs in top navigation. Since Labels and Milestones depends on Issue/MR feature it belongs to it and can be removed from top nav.

## What are the relevant issue numbers?

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/18368

## 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) - not needed
- [x] API support added - not needed
- [x] Tests
  - [x] Added for this feature/bug - changed existing tests to match new behaviour
  - [x] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)

cc @jschatz1 @annabeldunstone @skyruler

See merge request !4592

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

Add workhorse controller and API helpers

Adds `send_git_blob` and `send_git_archive` controller and API helpers to reduce duplication and make Workhorse easier for a developer to work with.

See merge request !4486

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

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

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

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

Updated CHANGELOG

Removed CHANGELOG entry

CI build page UI update

Closes #2569 

See merge request !3829

Update activity SVG path

## What does this MR do?
Fixes SVG path so the activity icon is the correct color

## Screenshots (if relevant)
<img src="/uploads/ea948338ea816890851a8011b8b3255f/Screen_Shot_2016-06-09_at_8.43.05_AM.png" width="600px">


See merge request !4563

Made the awardable buttons prettier when active

## What does this MR do?

Made the active and hover state of the award emoji buttons prettier.

## Why was this MR needed?

'cause @JobV wanted them to look nicer 😉 

## What are the relevant issue numbers?

Closes #18379 

## Screenshots (if relevant)

![Screen_Shot_2016-06-09_at_09.10.44](/uploads/5ecd0f12679e3484de1ab1d2dbe50cd8/Screen_Shot_2016-06-09_at_09.10.44.png)

See merge request !4554

Correctly shows label errors in dropdown

## What does this MR do?

Correctly shows any errors in the dropdown when creating a new label

## What are the relevant issue numbers?

Closes #18344 

## Screenshots (if relevant)

![Screen_Shot_2016-06-09_at_09.01.59](/uploads/58dc56b39db20a50adce6f12510025fc/Screen_Shot_2016-06-09_at_09.01.59.png)

See merge request !4553

Revert change to search all users

## What does this MR do?

Reverts a change that allowed the user to search for all users in the author/assignee dropdown

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

Double check it isn't still searching all users

See merge request !4564

Fixed project dropdown being overlapped by sidebar

## What does this MR do?

Changes the header expanded `padding` to `margin` to prevent the project dropdown from overlapping.

## What are the relevant issue numbers?

Closes #18410 

## Screenshots (if relevant)

![Screen_Shot_2016-06-10_at_10.38.00](/uploads/b569d6d4cbd126fd776cf849ebc1137d/Screen_Shot_2016-06-10_at_10.38.00.png)

See merge request !4583

Fixed issue where label filtering didnt work

## What does this MR do?

The filterable option was missing which meant labels in the dropdown couldn't be filtered. This fixes that.

## What are the relevant issue numbers?

Closes #18375 

See merge request !4556

Rename Commit to Pipeline in TriggerRequest

Changes in TriggerRequest a `commit` to `pipeline`.


See merge request !4505

Fix incorrect registry key value



See merge request !4595

Cache the presence of an issue_tracker at project level

See merge request !4466

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/18441

Using update_column to store the boolean flag to avoid
any side effects with the current state of the project
instance