2.0.1b4 Released!

Here's the change log:

* Supports comparing shapes, joints, bodies. Doesn't require using userData anymore.
* Major clean ups with Box2D.i
* Added some docstrings to Box2D.i functions
* Added b2PolygonDef.checkValues(): checks the Polygon definition to see if upon creation it will cause an assertion to fail (raises ValueError)
* Wrapped shape.GetCoreVertices() like GetVertices() (for test_TimeOfImpact)
* test_Web fixed
* All stuff prettily printed by a semi-automated process now
* Updated test_Bridge.py to SVN rev 156
* Added many comments to test_main