Updated mediawiki/extensions
Project: mediawiki/extensions/MobileFrontend  bf1cfa373e83ba8be983fa36584b0ae811531a89

Hygiene: Documentation for nearby code

Also fix up issue with EditorOverlayBase that is generating a
warning.

Change-Id: I124afe530157e0ebfc3b09a2c29e558a08c16fa9