Fixed typo in groups.md

Extended User API to expose admin and can_create_group for user creation...

* dont allow protect/unprotect branches for users without master permissions
* dont allow access to Repository api for guests

add rake tasks for web hooks management

Also, is_admin and can_create_group are exposed in the user information.
Fixed attributes_for_keys to process properly keys with boolean values (since false.present? is false).

run mysql_secure_installation to secure the freshly installed mysql server

[gitlab:check] Fix detecting the status of sidekiq

If you are running another sidekiq instance on your server, e.g. GitLab
CI, the check script would parse the output of `ps aux` searching for
`sidekiq` and returning success, although the GitLab sidekiq may not be
running.

Now the `ps` call will only print the processes run by the GitLab user.

Conflicts:
	app/controllers/projects/merge_requests_controller.rb

Fixed grammatical mistake in init.d status output.

"its" not "it's".

Add sleep in tests to prevent random failing when next test starts before ajax requests for old one in progress

Before we have only owner_id to determine group owner
With multiple owners per group we should get rid of owner_id in group.
So from now @group.owner will always be nil but
@group.owners return an actual array of users who can admin this group