Add comments to the SCSS Lint config file [ci skip]

This MR also adds some previously missing linters.

See merge request !3500

Add missing changelog item about improving navigation sidebar
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

For !3494 and #14838 

See merge request !3527

Fix Importing repos from GHE doesn't work

See merge request !3529

Add link to image URL for images in discussions.

The main problem with this is that it doesn't apply retroactively, only to images that are uploaded after this change. It's also hacky and probably not the most optimal solution.

Resolves #14411.

See merge request !3464

Resolves #14411.

See merge request !3464

Also add some previously missing linters.

Remove 2FA status on enable page

The 2FA status on the enabling page is useless, since it always is `disabled`. A user is enabling 2FA, so he already knows that it is disabled.

### Before

![Screenshot_2016-03-29_12.41.27](/uploads/4800a13a82f176077a11ecaf13ed0cb1/Screenshot_2016-03-29_12.41.27.png)

### After
![Screenshot_2016-03-29_12.40.55](/uploads/a77e8acd7cf99190bbd6bd340542ad10/Screenshot_2016-03-29_12.40.55.png)

See merge request !3436

GitHub Pull Requests importer handle with the repository while
importing data, we need to make sure that the cached values are valid.

Improve UI for admin/groups page
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

cc @jschatz1 @skyruler 

See merge request !3523

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

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

Set of UI fixes for admin area



See merge request !3525

Reload forked_project_link projects

See merge request !3526

Hide user profile activity graph on mobile

closes #14507 

## Before
![Screen_Shot_2016-03-26_at_10.28.21_PM](/uploads/5d5e2f77de936c2f2cd8a95132720a81/Screen_Shot_2016-03-26_at_10.28.21_PM.png)

## After
![Screen_Shot_2016-03-26_at_10.27.01_PM](/uploads/c011497b31368a0b7aa7d851541ac301/Screen_Shot_2016-03-26_at_10.27.01_PM.png)

## Medium width screen
![fix2](/uploads/2a5eb2d01f1a516991cd3e2b35b8aadc/fix2.gif)

See merge request !3412

Hide user profile activity graph on mobile

closes #14507 

## Before
![Screen_Shot_2016-03-26_at_10.28.21_PM](/uploads/5d5e2f77de936c2f2cd8a95132720a81/Screen_Shot_2016-03-26_at_10.28.21_PM.png)

## After
![Screen_Shot_2016-03-26_at_10.27.01_PM](/uploads/c011497b31368a0b7aa7d851541ac301/Screen_Shot_2016-03-26_at_10.27.01_PM.png)

## Medium width screen
![fix2](/uploads/2a5eb2d01f1a516991cd3e2b35b8aadc/fix2.gif)

See merge request !3412

Fix award emoji picker for relative_url

MR !2888 caused a regression where the emoji picker does not load when
using relative_url, because the path for the controller was hardcoded.

See merge request !3493

This fixes ./spec/services/projects/unlink_fork_service_spec.rb which
somehow started failing on the master branch. It certainly isn't a very
elegant solution but seems to be the easiest/best way of solving this
problem for the time being.

Add labels to block element

Fixes #14083 


Before:![Screen_Shot_2016-04-04_at_11.22.27_AM](/uploads/c35afd95ebca1b72f2aa37c72dc3c1a9/Screen_Shot_2016-04-04_at_11.22.27_AM.png)

After: ![Screen_Shot_2016-04-04_at_11.21.34_AM](/uploads/94f180858cf8fe2fc7eeec541ce66d44/Screen_Shot_2016-04-04_at_11.21.34_AM.png)

See merge request !3492

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

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

Fix event rendering when create project
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

cc @jschatz1 

See merge request !3522

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

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

Remove fork link closes all merge requests opened on source project

Currently, if you:

- create a fork
- open a merge request on the source project
- remove the fork link

The created MR cannot be closed.

With this MR, all pending MR is closed when the fork link is removed.

See merge request !3189

Fix transparent bg for expand sidebar button
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

For #14838 

cc @jschatz1 

See merge request !3520

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

Migrate Repository#local_branches from gitlab-ee.

REF: https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/249

This will help us to avoid posible merge conflicts when merging
gitlab-ce to gitlab-ee

See merge request !3496

Enable SpaceBeforeBrace rule for SCSS Lint

Also resolve all instances of spaces not being included before opening braces.

See merge request !3463

[ci skip]
Signed-off-by: Rémy Coutable <remy@rymai.me>

Fix creation of merge requests for orphaned branches with images

When attempting to create a merge request from an orphaned branch (e.g. this happens for the first commit of any repo) that contained images, GitLab would fail with a Error 500. This MR fixes that problem.

Closes #14875

See merge request !3511

Added 8.7 install/update guides

See merge request !3517

[ci skip]

Closes #14875

Improve rendering performance of Banzai

Related issues:

* gitlab-org/gitlab-ce#14315
* gitlab-org/gitlab-ce#13651

TODO:

* [x] `Banzai::Filter::ExternalIssueReferenceFilter#call` calls `Project#default_issues_tracker?` which runs a query on every call. Memoizing this only works if the `Project` instance is shared between instances of this filter. Either way it should at most only run this method once.
* [x] Fix the two failing specs
* [x] Clean of the various `call` methods in the filters where I inlined methods
* [x] Remove the `replace_XXX` methods in ReferenceFilter now that they're no longer used.

See merge request !3389

Cleaning this up any further is a bit tricky as the caches in question
should only be evaluated if RequestStore is actually enabled.

Fix bug related to filtering Issues by Label/Milestone.

See merge request !3499