Add issues filters reset btn

## What does this MR do?

Adds a button to the issues filter to reset all filters. I also lightly refactored a nearby method.

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

At the moment, the user can click the reset button even when no filters have been set. I didn't really like how it looked flashing the link on and off depending on whether a user had added a filter. I prefer having it there all the time, so the user is aware of it. But it wouldn't be difficult to hide if no filters have been set, if that's preferred.

## Why was this MR needed?

So users can reset filters when they're filtering issues.

## What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ce/issues/14016

## Screenshots (if relevant)

![reset-filters](/uploads/562916158ce7b0179794e19f88f5c2e3/reset-filters.png)

## 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
- 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 !5330

Fix: Switch sample values for $CI_SERVER_REVISION and $CI_SERVER_VERSION.

See the general Documentation guidelines http://docs.gitlab.com/ce/development/doc_styleguide.html.

## What does this MR do?

There is a sample in this document showing the possible values of the predefined CI variables. Those of **CI_SERVER_REVISION** and **CI_SERVER_VERSION** were mixed up. I fixed that.

See merge request !6243

API for CI Lint

## What does this MR do?
Add API for CI Lint. Can check if `.gitlab-ci.yml` content is valid.

## What are the relevant issue numbers?
Closes #15571 

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [x] API support added
- [x] Documentation
- Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing

cc @ubudzisz @grzesiek @yorickpeterse

See merge request !5953

Issue #21440: Small fix to curl example for adding member to project

## What does this MR do?
Two lines changed in docs to move the user_id field out of the url and onto the query string 

## Why was this MR needed?
Issue #21440 reported under Issues. The documentation example for adding members to a project had a slight problem. 

## What are the relevant issue numbers?
Closes #21440.

See merge request !6236

Gitlab -> GitLab

## What does this MR do?
Fix GitLab capitalization

See merge request !6235

Lighten color of created icon

#### What does this MR do?
Changes `created` icon color to lighter gray

#### Screenshots (if relevant)
![Screen_Shot_2016-09-06_at_10.25.19_AM](/uploads/6543d0004d817adcbe13cc2b23b6b7bb/Screen_Shot_2016-09-06_at_10.25.19_AM.png)
cc @dimitrieh

See merge request !6230

API: Add the ability to fork to a specific namespace

Browser interface allows forking to an owned grup.
This commit brings API up to speed by providing optional namespace
parameter to fork API. This allows forking to users and groups under
forker's control using their id or unique name.

Fixes #21591 

## 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
- Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [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 !6213

Merge branch '18851-commit-text-in-activity-commits-page-etc-has-the-wrong-line-height' into 'master'

Changed `.commit-row-title` `line-height` to `1.35` from `1`

## What does this MR do?

Changes `.commit-row-title` `line-height` to `1.35` from `1`, this is to match the `line-height: 20px;` from before 41c2ea9b.

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

## Why was this MR needed?

Not enough space between commit lines

## What are the relevant issue numbers?

Closes #18851.

## Screenshots (if relevant)

New screenshot below.

## 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)
Closes #18851

See merge request !5996

Reduce intermittent spec failures by making VueJS resource interceptor decrement outstanding resource counts when HTTP response is received

Before the count would be reduced 500 ms after a DOM update tick, which could cause race conditions since the `DatabaseCleaner` could run in the middle of a Rails controller handling the response.

Partial fix to #21197 and other intermittent spec failures.

See merge request !6224

increased checkbox and filter button padding

## What does this MR do?

fixed misalignments as described in https://gitlab.com/gitlab-org/gitlab-ce/issues/19110

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

Not that I know of

## Why was this MR needed?

https://gitlab.com/gitlab-org/gitlab-ce/issues/19110

## Screenshots (if relevant)

![image](/uploads/e7c5ffe78e1a5b67fa0335ba1c231df2/image.png)

![image](/uploads/1591ed872e765da3b5ed071c8872194f/image.png)

## 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
- [ ] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [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)


## What are the relevant issue numbers?

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/19110

See merge request !6206