btRaycastVehicle and btKinematicCharacterController are derived from btActionInterface now.
Some cosmetic cleanup: changed sourceforce/sf.net url to bulletphysics.com.
Added very basic drawTriangle for btIDebugDraw, useful for basic softbody visualization.
Added btGjkEpa2, contribution by Nathanael Presson. Improved version of EPA penetration depth computation, more suitable for multi-core/SPU (less memory usage). Note: btGjkEpa2 is not enabled by default currently.