draft of the a CLI using Thor

I think a Thor based CLI might be easier than using a rake task.
Unfortunately this adds thor as a dependency, but I think that should not be a problem.

This is an example of how thor could be used. It needs to be tested and extended. (action description blocks are missing). 
Also i have not updated the readme. 

Usage:

./buildbox-cli 
./buildbox-cli -h
./buildbox-cli build [DEFINITON]
....