Updated mediawiki/extensions
Project: mediawiki/extensions/MobileFrontend  128f3492fb7017c960bba0fb74a790c6f37b08c1

Hygiene: Reshuffle content / page action overlays

Demote ContentOverlay from common since only used in one place.
Add some documentation to tutorial files to explain what they do.

Prevent duplication in Resources.php

Change-Id: I882c6835d9a67f70c49d0b8f27b2b8532efc0f8f