Merge pull request #1 from Kovak/master

Addition of Boxshape and space.add_collision_handler
Merge pull request #2 from Kovak/master

Fixed apply_force
Merge pull request #3 from Kovak/master

Added segment query
Changed ApplyForce, ApplyImpulse to take tuples instead of dicts, changed rotation_vector to return a Vec2d instead of a dict of ['x', 'y']
Recommit of last commit because git through a weird error and pushed half of the changes without logging them
Poly shape creation
Merge branch 'master' of https://github.com/tito/cymunk
Get Poly class worked