Hide and show icons in collapse and expanded mode.

[WIP]

Remove link from system hook

Closes #12672

See merge request !2588

Bump octokit to `~> 3.8.0`

Closes #2877

See merge request !2536

Fix hot reloading for CI API



See merge request !2617

Refactor forking workflow documentation

Closes #5974 

See merge request !2623

[ci skip]

Use generic method to checks if artifacts are available

Closes #12626

See merge request !2576

Fix typo on artifacts doc



See merge request !2622

[ci skip]

[ci skip]

Update ExternalIssue regex for JIRA integration

The pattern in the `::reference_pattern` class method in the
`ExternalIssue` model does not match all valid forms of JIRA project
names. I have updated the regex to match JIRA project names with numbers
and underscores. More information on valid JIRA project names can be
found here:
https://confluence.atlassian.com/jira/changing-the-project-key-format-192534.html

* The first character must be a letter,
* All letters used in the project key must be from the Modern Roman Alphabet and upper case, and
* Only letters, numbers or the underscore character can be used.

See merge request !2598

The pattern in the `::reference_pattern` class method in the
ExternalIssue model does not match all valid forms of JIRA project
names. I have updated the regex to match JIRA project names with numbers
and underscores. More information on valid JIRA project names can be
found here:
https://confluence.atlassian.com/jira/changing-the-project-key-format-192534.html

* The first character must be a letter,
* All letters used in the project key must be from the Modern Roman Alphabet and upper case, and
* Only letters, numbers or the underscore character can be used.

Bug/jschatz1/file browser lines

Fixes #12725 

![Screen_Shot_2016-01-26_at_11.19.39_AM](/uploads/c5f5a143926600e02de4cfc0687ed8dd/Screen_Shot_2016-01-26_at_11.19.39_AM.png)


See merge request !2615

Bump Workhorse version to 0.6.2

Fix for #12634 has been introduced in gitlab-org/gitlab-workhorse!34.

See merge request !2616

Merge branch 'search-box-in-group-members-view-is-too-small-for-placeholder-in-chrome' into 'master'

Fixes: Search box in Group Members view is too small for placeholder in Chrome

Fixes #2498 

![Screen_Shot_2016-01-25_at_11.55.57_PM](/uploads/de4fda98cd8552641208b3a7a9277e35/Screen_Shot_2016-01-25_at_11.55.57_PM.png)


See merge request !2609

This has been fixed in Workhorse [ci skip]

Fix for #12634 has been introduced in gitlab-org/gitlab-workhorse!34.

Monkey patch for mysql 5.7



See merge request !2597

Uses `$border-color`

Clicks the edit button instead of opening the dropdown

Fixes #2307 

Instead of opening the menu, this clicks the `edit` button.

See merge request !2607

This reverts commit a1408948.

This reverts commit 11183488.

Fixes #12725

Fix visibility level texts on application settings

Introduced by me through !2005

Before:

![Screenshot_from_2016-01-26_09-34-09](/uploads/fa3e8f2522a1d26372c7a06a81119e6f/Screenshot_from_2016-01-26_09-34-09.png)

After:

![Screenshot_from_2016-01-26_09-34-27](/uploads/7955003dd02dd5376c9966aafdf4c50b/Screenshot_from_2016-01-26_09-34-27.png)


See merge request !2611

Introduced by me through !2005

New download btn WIP.

Save button on app settings now btn-save

Some save buttons where `btn-primary` where throughout the application these usually are `btn-save`.

Before (Application settings)

![Screenshot_from_2016-01-26_09-44-32](/uploads/f4019349c8bac6e0c91e23252a70d334/Screenshot_from_2016-01-26_09-44-32.png)

After

![Screenshot_from_2016-01-26_09-45-20](/uploads/8e59a2b180832f44e3908b22187549af/Screenshot_from_2016-01-26_09-45-20.png)


See merge request !2612

Track project import failure

Fixes #12512 

This also help us on identify why the import process is returning the wrong status when the project was successfully imported. Like mentioned in the issue #12450 

See merge request !2538

Add tests for clicking a row in build artifacts browser

This adds a feature tests for clicking a row, which is handled by javascript event.

/cc @ayufan 

See merge request !2551