fixed memoryleak,

added RayTestSingle to CollisionWorld
prepared to add VehicleDemo

Bullet/BroadphaseCollision/OverlappingPairCache.cpp

@@ -101,6 +101,7 @@ void	OverlappingPairCache::AddOverlappingPair(BroadphaseProxy* proxy0,Broadphase
 ///this FindPair becomes really slow. Either sort the list to speedup the query, or
 ///use a different solution. It is mainly used for Removing overlapping pairs. Removal could be delayed.
 ///we could keep a linked list in each proxy, and store pair in one of the proxies (with lowest memory address)
+///Also we can use a 2D bitmap, which can be useful for a future GPU implementation
 BroadphasePair*	OverlappingPairCache::FindPair(BroadphaseProxy* proxy0,BroadphaseProxy* proxy1)
 {
 	BroadphasePair* foundPair = 0;