Issue 28

PLEASE DO NOT MERGE THIS YET, at least without testing it and looking at it.  This is my first ever time writing code for a parser :-)

This is a proof of concept for what I was talking about.  It kind of works, but is very fragile.  (emmet-find-left-bound) needs to be replaced with something better, definitely, and I'm not sure that what I did with the parser stuff is the right way to do it.