CompoundShapes are tricky to manage with respect to persistent contact points and swapped order of btCollisionObjects,
During dispatch, finding an algorith etc. order can be swapped.
fixed several other issues, related to SimpleBroadphase (removing a proxy was not working)
Fixed memoryleak in btOptimizedBvh (delete []m_contiguousNodes;)
Changed DemoApplication::localCreateRigidBody, so it adds the rigidbody to the btDynamicsWorld.
Added check for duplicate objects in world when adding.
Added assert to prevent setLinearVelocity on static rigidbodies
Added btCollisionFilterGroups to btBroadphaseProxy
removed duplicate 'btBroadphaseProxy* m_broadphaseProxy;' in btRigidBody
removed two cached optimizations, type in btTransform and cached inverse transform (todo: test performance impact)
committed fixes that make the code adhere to 'who creates it, also destroys it'
