Remove UTF-8 BOMs

These make it hard to determine which files have mixed CRLF+LF line
endings, because dos2unix and unix2dos strip them. In case other tools
also aren't impressed and since they're not often needed, remove them
where it seems they're not needed.

The BOMs were left for the input files for the HTML and WebVTT parser
tests, where they are obviously intentional.

Removed with `git ls-tree -r --name-only HEAD | xargs -n1 bomstrip-files`
and manual inspection of the results.
Merge branch 'master' into bomstrip

Conflicts:
	2dcontext/fill-and-stroke-styles/canvas_colorsandstyles_addcolorstop_001.htm
	harness/harness.htm
	harness/loader.htm
	old-tests/submission/Microsoft/audio/audio_004.htm
	old-tests/submission/Microsoft/audio/audio_005.htm
	old-tests/submission/Microsoft/canvas/canvas_colorsandstyles_addcolorstop_001.htm
	reporting/IE9_PPB4.xml

These were all deleted on master after the bomstrip branch.

bomstrip was run again to verify that no new BOMs have appeared.