Make tests.html comply with http://validator.w3.org
Dump //@ sourceURL= variant, use just //# sourceURL=

For some versions of firefox and chromium they support //# now,
and on debugging all the deprecated warnings at least with firefox
are annoying
Workaround for Firefox failing on RemoveText_CopesWithEmptyTextNodes
Merge pull request #761 from kossebau/browserTestsTwisting

Workaround for Firefox failing on RemoveText_CopesWithEmptyTextNodes