improved performance of constraint solver by precalculating the cross product/impulse arm
added collision comparison code: ODE box-box, also sphere-triangle
added safety check into GJK, and an assert for AABB's that are very large
write partid/triangle index outside of GJK
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)
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'
