Started working on CSS matching library.

We're using tinycss for parsing, but it doesn't do much more than
tokenize the selectors, so most of this commit is parsing selectors.

I've also commented out a few of the rules in the test css, since the
parser currently can't handle them.
Merge branch 'master' of github.com:sterling-ui/prototype

Conflicts:
	tests/data/test1.css