add rake target to run unit tests
Add lemon to dependencies for qbparse.c

Doing a fresh git clone from the main qbrt repository and running
rake fails trying to call 'lemon', because its doesn't exist yet.
This makes sure that lemon is built before it's called
Merge pull request #1 from hoelzro/master

Add lemon to dependencies for qbparse.c

Thanks for the pull request!
updates to the README docs

more to come still
Merge branch 'master' of git://github.com/mdg/qbrt