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

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

Fix UTF-8 handling in incremental trace update API

## What does this MR do?

This MR fixes invalid UTF-8 handling in incremental trace update API (used by GitLab Runner).

## Why was this MR needed?

Current version is using `.length` method to determine current trace size where Runner is using the trace size in bytes. Also this byte size is used in headers and file operations to agree the trace part to send. This is a problem when build trace contains any multi-byte UTF-8 characters. This MR is fixing this situation so all parts are using the same size in bytes.

### Runner -> API communication before fix:
```
Checking for builds... received                     runner=_token_
gitlab-ci-multi-runner 1.3.0~beta.26.gcfd63b9 (cfd63b9)  build=25 runner=_token_
Using Docker executor with image debian:jessie ...  build=25 runner=_token_
Pulling docker image debian:jessie ...              build=25 runner=_token_
25 Submitting build to coordinator... ok            runner=_token_
25 Appending trace to coordinator... ok             RemoteRange=0-158 RemoteState=running ResponseMessage=202 Accepted ResponseStatusCode=202 SentRange=0-158 runner=_token_
25 Appending trace to coordinator... ok             RemoteRange=0-491 RemoteState=running ResponseMessage=202 Accepted ResponseStatusCode=202 SentRange=158-505 runner=_token_
WARNING: 25 Appending trace to coordinator... range missmatch  RemoteRange=0-491 RemoteState= ResponseMessage=416 Requested Range Not Satisfiable ResponseStatusCode=416 SentRange=505-584 runner=_token_
WARNING: 25 Resending trace patch due to range missmatch  runner=_token_
25 Appending trace to coordinator... ok             RemoteRange=0-556 RemoteState=running ResponseMessage=202 Accepted ResponseStatusCode=202 SentRange=491-584 runner=_token_
WARNING: 25 Appending trace to coordinator... range missmatch  RemoteRange=0-556 RemoteState= ResponseMessage=416 Requested Range Not Satisfiable ResponseStatusCode=416 SentRange=584-663 runner=_token_
WARNING: 25 Resending trace patch due to range missmatch  runner=_token_
25 Appending trace to coordinator... ok             RemoteRange=0-621 RemoteState=running ResponseMessage=202 Accepted ResponseStatusCode=202 SentRange=556-663 runner=_token_
Build succeeded                                     build=25 runner=_token_
WARNING: 25 Appending trace to coordinator... range missmatch  RemoteRange=0-621 RemoteState= ResponseMessage=416 Requested Range Not Satisfiable ResponseStatusCode=416 SentRange=663-797 runner=_token_
WARNING: 25 Resending trace patch due to range missmatch  runner=_token_
25 Appending trace to coordinator... ok             RemoteRange=0-741 RemoteState=running ResponseMessage=202 Accepted ResponseStatusCode=202 SentRange=621-797 runner=_token_
25 Submitting build to coordinator... ok            runner=_token_
```

### Runner -> API communication after fix:
```
Checking for builds... received                     runner=_token_
gitlab-ci-multi-runner 1.3.0~beta.26.gcfd63b9 (cfd63b9)  build=26 runner=_token_
Using Docker executor with image debian:jessie ...  build=26 runner=_token_
Pulling docker image debian:jessie ...              build=26 runner=_token_
26 Submitting build to coordinator... ok            runner=_token_
26 Appending trace to coordinator... ok             RemoteRange=0-158 RemoteState=running ResponseMessage=202 Accepted ResponseStatusCode=202 SentRange=0-158 runner=_token_
26 Appending trace to coordinator... ok             RemoteRange=0-505 RemoteState=running ResponseMessage=202 Accepted ResponseStatusCode=202 SentRange=158-505 runner=_token_
26 Appending trace to coordinator... ok             RemoteRange=0-584 RemoteState=running ResponseMessage=202 Accepted ResponseStatusCode=202 SentRange=505-584 runner=_token_
26 Appending trace to coordinator... ok             RemoteRange=0-663 RemoteState=running ResponseMessage=202 Accepted ResponseStatusCode=202 SentRange=584-663 runner=_token_
Build succeeded                                     build=26 runner=_token_
26 Submitting build to coordinator... ok            runner=_token_
```

See merge request !4541

Add option to restrict merge MR with failed build

_Originally opened at !3828 by @ruianderson._

-----

## What does this MR do?

This MR adds an option to prevent MR from being merged if their build status is not a success. Please note that if the MR has no `ci_commit`, the MR can be merged (i.e. we don't enforce builds to be configured).

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

Probably the copy in the edit project's page and in the documentation.

## What are the relevant issue numbers?

Closes #5940.

## Screenshots

![only_allow_merge_if_build_succeeds](/uploads/bb43cf131f680c9af0eb2ea5155189e0/only_allow_merge_if_build_succeeds.png)

See merge request !4503

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

The logic of the method was obviously inverted.
Signed-off-by: Rémy Coutable <remy@rymai.me>

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

Based on the feedback from reviewers.
Signed-off-by: Rémy Coutable <remy@rymai.me>

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

Don't require Gitlab::Redis in mail_room.yml if it's already defined

## What does this MR do?

Avoid requiring `lib/gitlab/redis.rb` if `Gitlab::Redis` is already defined.

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

No.

## Why was this MR needed?

Because otherwise you get `already initialized constant Gitlab::Redis::XXX`, e.g.:

```
› bin/rspec spec/config/mail_room_spec.rb
Running via Spring preloader in process 24658
/Users/remy/Code/GitLab/gdk/gitlab/lib/gitlab/redis.rb:3: warning: already initialized constant Gitlab::Redis::CACHE_NAMESPACE 
/Users/remy/Code/GitLab/gdk/gitlab/lib/gitlab/redis.rb:3: warning: previous definition of CACHE_NAMESPACE was here
/Users/remy/Code/GitLab/gdk/gitlab/lib/gitlab/redis.rb:4: warning: already initialized constant Gitlab::Redis::SESSION_NAMESPACE
/Users/remy/Code/GitLab/gdk/gitlab/lib/gitlab/redis.rb:4: warning: previous definition of SESSION_NAMESPACE was here
/Users/remy/Code/GitLab/gdk/gitlab/lib/gitlab/redis.rb:5: warning: already initialized constant Gitlab::Redis::SIDEKIQ_NAMESPACE
/Users/remy/Code/GitLab/gdk/gitlab/lib/gitlab/redis.rb:5: warning: previous definition of SIDEKIQ_NAMESPACE was here
/Users/remy/Code/GitLab/gdk/gitlab/lib/gitlab/redis.rb:12: warning: already initialized constant Gitlab::Redis::URL_MUTEX
/Users/remy/Code/GitLab/gdk/gitlab/lib/gitlab/redis.rb:12: warning: previous definition of URL_MUTEX was here
/Users/remy/Code/GitLab/gdk/gitlab/lib/gitlab/redis.rb:13: warning: already initialized constant Gitlab::Redis::POOL_MUTEX
/Users/remy/Code/GitLab/gdk/gitlab/lib/gitlab/redis.rb:13: warning: previous definition of POOL_MUTEX was here
 2/2 |================================================= 100 =================================================>| Time: 00:00:00 

Finished in 0.38505 seconds (files took 0.48292 seconds to load)
2 examples, 0 failures
```

## 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~~ Not needed.
- [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.~~ Not needed.
- [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 !4586

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

Closes #18410

Added sidebar
Removed elements not present in design

Add Issue/PR Templates to deter issues/contributions on the GitHub mirror of the project

## What does this MR do?
Adds GitHub-specific `ISSUE_TEMPLATE.md` and `PULL_REQUEST_TEMPLATE.md` files in a `.github` directory. To prevent new issues/PRs, I figured it'd be good to direct users/contributors to open issues/contribute code in the "correct" project.

## Are there points in the code the reviewer needs to double check?
Wording/phrasing, mostly.

## Why was this MR needed?
The GitHub issue tracker is being closed, and PRs on GitHub haven't been accepted for a while now. This was discussed briefly during the GitLab Strategy Session at the Austin Summit.

cc: @dzaporozhets @rymai  @MrChrisW @dblessing @virtuacreative @amara  

See merge request !4324

Enable RuboCop for migrations

## What does this MR do?

Enable RuboCop for all files inside `db/migrate`, then add magic comments to all existing files, so that this only affects new migrations.

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

This entire change is a config change and a bunch of comments.

## Why was this MR needed?

```
Yorick Peterse [11:55 AM]  
I don't think we have any use case for nested def, might as well blacklist it

Sean McGivern [11:57 AM]  
http://www.rubydoc.info/gems/rubocop/RuboCop/Cop/Lint/NestedMethodDefinition

Sean McGivern [11:57 AM]  
hmm, it's already enabled

Sean McGivern [11:57 AM]  
... because we exclude `db/` from rubocop 🙂

Douwe Maan [11:57 AM]  
@smcgivern: heh

Sean McGivern [11:59 AM]  
I guess that's because we don't want to change the old migrations? I wonder if it's worth enabling it and adding magic comments to all the previous ones to ignore rubocop

Douwe Maan [11:59 AM]  
@smcgivern: agreed
```

## What are the relevant issue numbers?

None.

## Screenshots (if relevant)

None, but if I remove the magic comment from the migration `20160416182152_convert_award_note_to_emoji_award.rb` I get:
```
$ be rubocop
Inspecting 1959 files
..................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................W....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

Offenses:

db/migrate/20160416182152_convert_award_note_to_emoji_award.rb:3:5: W: Lint/NestedMethodDefinition: Method definitions must not be nested. Use lambda instead.
    def up ...
    ^^^^^^

1959 files inspected, 1 offense detected
```

## 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 !4559

Wrap all rate limiting logic inside GitHub API client

## What does this MR do?

Move the actual rate limiting logic to GitHub API to clean the code inside the GitHub importer, and avoid code duplication.

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

No there aren't.

## Why was this MR needed?

Avoid code duplication to handle API rate limit in every call to the GitHub API.

## What are the relevant issue numbers?

There are none.

## Screenshots (if relevant)

Not relevant.

See merge request !4552

Fixes #18344