Create autopatrolled user group on brwikimedia

Since sysops are already able to add users to this
group, it would be nice to actually have it, too.

Requires setting $wgUseRCPatrol to 'true', which
I'm doing after a comment from Lestaty, who speaks
on behalf of the user group.

Bug: 63345
Change-Id: Ib18fd0ac5a06ebbcea0f93fd25376561389dd6f1