Cleanup bugfiler.js (#2151)
Cleanup bugfiler.js (#2151)

Changes split out from the autoclassification UI rewrite branch, and
are just minor cleanup of the existing code.
edmorley/treeherder,kapy2010/treeherder,tojon/treeherder,edmorley/treeherder,tojonmz/treeherder,edmorley/treeherder,KWierso/treeherder,tojon/treeherder,KWierso/treeherder,tojonmz/treeherder,KWierso/treeherder,tojonmz/treeherder,tojon/treeherder,tojonmz/treeherder,kapy2010/treeherder,tojonmz/treeherder,tojon/treeherder,kapy2010/treeherder,edmorley/treeherder,kapy2010/treeherder,tojonmz/treeherder,KWierso/treeherder,kapy2010/treeherder