Rewrite footer how skins do it

This rewrites the footer in a desktop compatible way
Make footer css available for all pages
Don't give the main page mw-mf-special use page-Main_Page as it
is on desktop

Change-Id: I1253edfaa5af3d7782a87caf2e3ab0c9b3ae66f0
Merge "Rewrite footer how skins do it"