Updated mediawiki/extensions
Project: mediawiki/extensions/MobileFrontend  31ca834cfba78e4409c13ff7aecd0f4f91f5724e

Rotate escape overlay arrow for RTL languages

Also, delete unused arrow images and pngcrush the one we use.

Change-Id: If0358d185331b1954171bbb0b165ea500e44e07f