Change-Id: I3af726e7f3eee3b967f6f43fd7efa95e298b549c
Change-Id: Id558f0990c87332b252a8721fff9a1c8fa0597bf
This is the final step of the process described at <https://www.mediawiki.org/wiki/Separating_skins_from_core_MediaWiki>. Corresponding core change: Idfc38503. Change-Id: I83b1efb4a489254c76e0cbda72ff34efa3d41261