Allows ordering in GET api/v4/projects/:project_id/repository/contributors
through `order_by` and `sort` params.
The available `order_by` options are: name|email|commits.
The available `sort` options are: asc|desc.

Prevent creating issues through API without having permissions

See merge request gitlab/gitlabhq!2225

(cherry picked from commit c298bbaa88883343dc9cbbb6abec0808fb3b546c)

915b97c5 Prevent creating issues through API without having permissions

[10.2] Ensure we expose group projects using GroupProjectsFinder

See merge request gitlab/gitlabhq!2234

(cherry picked from commit 072f8f2fd6ec794645375a16ca4ddc1cbeb76d7a)

a2240338 Ensure we expose group projects using GroupProjectsFinder

Moving the check out of the general requests, makes sure we don't have
any slowdown in the regular requests.

To keep the process performing this checks small, the check is still
performed inside a unicorn. But that is called from a process running
on the same server.

Because the checks are now done outside normal request, we can have a
simpler failure strategy:

The check is now performed in the background every
`circuitbreaker_check_interval`. Failures are logged in redis. The
failures are reset when the check succeeds. Per check we will try
`circuitbreaker_access_retries` times within
`circuitbreaker_storage_timeout` seconds.

When the number of failures exceeds
`circuitbreaker_failure_count_threshold`, we will block access to the
storage.

After `failure_reset_time` of no checks, we will clear the stored
failures. This could happen when the process that performs the checks
is not running.

CE backport of "ProtectedBranches API handles per user/group granularity"

See merge request gitlab-org/gitlab-ce!15747

In EE we now allow individual users/groups to be set on POST, which required some refactoring.
See https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/3516

Multiple artifacts

See merge request gitlab-org/gitlab-ce!14367