Grapify builds API

## What does this MR do?

Add the Grape-DSL to the builds API.

## What are the relevant issue numbers?

Related to #22928 

The artifacts API directly downloads a file rather then returning a JSON entity.

See merge request !6877

Fix old monitoring links to point to the new location

See merge request !7075

Add an example of how to run the backups when using docker to the docs

## What are the relevant issue numbers?

https://gitlab.com/gitlab-org/omnibus-gitlab/issues/1616

See merge request !7046

See merge request !4814.

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

fixes build with cache:clear issue

## What does this MR do?
Fixes a build issue that was probably introduced in commit 0c0caede.

See merge request !7074

Check that user has access to a given namespace to prevent leaking namespace names.

See merge request !2009

See merge request !6544.

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

Merge request - https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6979

Fix branch protection API.

## What does this MR do?

- Fixes the branch protection API.
- Closes #21513 
- EE Merge Request: gitlab-org/gitlab-ee!718

## Tasks

- [ ]  #21513 !6215 Protected branches API bug
    - [x]  Investigate
    - [x]  Test + Fix
    - [x]  Changelog
    - [x]  MR
    - [x]  Wait for build to pass
    - [x]  Review
    - [x]  Check for EE conflicts
    - [x]  Create EE MR
    - [x]  Refactor + Fix
    - [x]  Rebase EE MR against EE master
    - [x]  Wait for builds to pass
    - [x]  Assign to dbalexandre/douwe
    - [x]  Implement latest review comments
    - [x]  Wait for Douwe's review
        - [x]  Implement changes
        - [x]  Port changes to EE MR
        - [x]  Assign both back to Douwe
    - [ ]  Wait for merge
    - [ ]  Merge gitlab-org/gitlab-ee!718

See merge request !6215

Fix constrainers for relative url

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/23675

See merge request !7071

Use root_url for issue boards user link

## What does this MR do?

Rather than using `/` as the root path, it now correctly sends the root URL from Rails to prevent errors with installations in subdirectories. 

## What are the relevant issue numbers?

Closes #23556

See merge request !7018

This MR removes AR before_validation callback in favor setter.

## Why was this MR needed?

Because setters is good practice to normalize model attributes instead AR callbacks. Because new object should be valid right after initialization. 
If it MR interested I can try to find other places where we can use setters.

See merge request !6763

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

Moves `spec/mailers/shared/notify.rb` to `spec/support/notify_shared_examples.rb`

Closes #22609 

See merge request !6605

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>

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>

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

- Disable {project, group} members submit button if no users

  If no users are selected, the submit button should be disabled.

- Alert user when no users were added to {project, group}.

  When no users were selected for adding, an alert message is
  flashed that no users were added.

- Also, this commit adds a feedback when users were actually added to a
  project, in symmetry with how group members are handled.

Closes #22967, #23270.

This reverts commit c81ff152.

Fix reply-by-email not working due to queue name mismatch

See merge request !7068

Closes #23556

removes extra line for empty description

## What does this MR do?
This MR removes an odd line for empty description 
## Are there points in the code the reviewer needs to double check?
Not necessary
## Why was this MR needed?
Improve UX 
## Screenshots (if relevant)
**Before**
![ss__2016-10-19_at_11.04.45_PM](/uploads/12b376c772115c2e5eef2fe0c0d1992f/ss__2016-10-19_at_11.04.45_PM.png)
**After**
![edi](/uploads/89fea59ef5267974af4cbe1064dc521a/edi.png)
## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG.md) 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
  - [ ] Added for this feature/bug
  - [ ] 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 it does - 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 #23557 #23695

See merge request !7045

Document link syntax introduced by !5586.

See merge request !7049

* master: (22 commits)
  Fix status code expectation
  Stop clearing the database cache on rake cache:clear
  Fix error in generating labels
  Fix bug where e-mails were not being sent out via Sidekiq
  Fix documents and comments on Build API `scope`. #23146 #19131
  Re-organize queues to use for Sidekiq
  Fix wrong endpoint in api/users documentation, fix same typo in spec describe blocks
  Update CHANGELOG
  Fix object data to be sent to fetch analytics data
  Fixed compare ellipsis messing with layout
  Change "Group#web_url" to return "/groups/twitter" rather than "/twitter".
  fix font weight of project feature settings
  Add hover to trash icon in notes
  Ensure custom provider tab labels don't break layout.
  Fixed issue when images are loading it would push off the tabs
  Fixed issues with sticky mr tabs & sidebar
  Refactor and add new functionality to CI yaml reference
  Ignore external issues when bulk assigning issues to author of merge request.
  Changed gitlab-shell version to avoid warning when precompiling the assets.
  Grammar fixes in docs
  ...

Extract/mutate `params` in the `execute` method of the API services,
rather than in `initialize`.

- Pass `developers_and_merge` and `developers_can_push` in `params`
  instead of using keyword arguments.

- Refactor a slightly complex boolean check to a simple `nil?` check.