add support clear: fix;
codestyle fix spaces
hey, @visionmedia, can you look at this pr? It's rather small, so it won't take much time to check it
i'm not sure if we want to integrate the term "clearfix" further... IMO, "group" makes much more sense. however, if this makes sense to other people I'd be open to merging it.
btw, nice test cases... everything about this PR, other than the concern mentioned above, looks great