Some performance improvements and fixes related to btVector3 being aligned on SPU.

btQuantizedBvh has a version number, memory layout might be different now (due to aligned btVector3)
reorganized some data members of some classes, to reduce memory footprint

src/BulletMultiThreaded/SpuNarrowPhaseCollisionTask/SpuMinkowskiPenetrationDepthSolver.cpp

@@ -338,7 +338,7 @@ bool SpuMinkowskiPenetrationDepthSolver::calcPenDepth( SpuVoronoiSimplexSolver&
 
 	} else {
 		// could not seperate shapes
-		btAssert (false);
+		//btAssert (false);
 	}
 	return res.m_hasResult;
 }