Adds buoyancy tests (although it is not working due to no collision callbacks).
And adds missing functions in body/shape.
Initial buoyancy demo test for chipmunk-js
AngularVelocity, and sensor added to lib/cpBody / lib/cpShape
Updated cp.min.js as well
the buoyancy test now working in Cocos2d-html5 + Cocos2d-js-tests