bugfix: propagate the progress
added comments for Csg.cube
remove debugging
added Csg sphere
added 'when' package
add build bps with 'when' promises
simplified calls to resolve promise in Q
refactored geometry to use when instead of Q and async
refactor buildAsyncWithPromise to completely
use when promises
added some comments
increase the polygon count in tests
change partitionPolygons to return the polygonType
bugfix: progress handlers weren't firing, because
the promise was being resolved too quickly, so the
handlers weren't attached before the progress was
fired.
refactor geometry to use common splitPolygon,
and remove async partitionPolygon, since it'll 
be too slow.
added profiling test for building with callback