Add setting wgLogAutopatrol to toggle logging of autopatrol actions

Per bug 47415, this is needed for Wikidata and could be useful for
other wikis, as well.

Bug: 47415
Change-Id: Ic999454d001c38dea08746d1e8184f0163cb7330
Merge "Add setting wgLogAutopatrol to toggle logging of autopatrol actions"