(bug 7851) Implement mediawiki.page.patrol.ajax

(bug 7851) Implement mediawiki.page.patrol.ajax

Implement AJAX patrolling with the new mediawiki.page.patrol.ajax
module, which makes use of the API via mediawiki.api.

During the patrol process a spinner (created by jquery.spinner)
shows up and after it a suitable message gets shown via
mediawiki.notify.

Depending on whether we had success or not the link then turns up
again or the brackets completely disappear just like on a normal page view.

On top of adding the module, I've changed the following:
- Added the patrol token to the ResourceLoaderUserTokensModule.
- Registered messages 'markedaspatrollednotify' and
  'markedaspatrollederrornotify'.

Change-Id: I472357566dda0ab572c20e2e4b87508b0f2f4c73