Updated mediawiki/extensions
Project: mediawiki/extensions/MobileFrontend  b0c98758b83f7828204c05d4269864a5766db725

Hygiene: Make 'make clean' clean up all existing documentation

Helps when I need to grep..

Change-Id: I82f0e80b4e21a175fe8f0b6c1610cadacc3df893