With apologies to anyone who gets a hundred merge conflicts
because of this :)
We had several different prefix styles (mlb-, mw-mlb-, mw-mmv-,
mw-mmv-mmv-, a few unprefixed), which was getting annoying,
and will be confusing to wiki editors who are trying to figure out
where a given style comes from. Such changes are better done before
going live because it breaks all local CSS tweaks on the wiki,
so I am renaming things now (also removing some stuff which wasnt
used anywhere).
Change-Id: I00447a25f0028e234169c6db941bedc99622eb8d
fileUsage tests were applying styles to the fixture element, which
apparently does not get cleaned between tests. This was because
fileUsage.$container had different semantics from element.$container
(widget's own container div vs. parent container div). FileUsage
now inherits from Element to make sure behavior is consistent.
Change-Id: I8fab8bcf084d8b7e480655114506d9848e9d9a49
