Share btGjkPairDetector, btGjkEpa2, btVoronoiSimplexSolver with SPU/Multithreaded implementation (remove duplicate code)

Make btTypedConstraint and btPersistentManifold both derive from btTypedObject to make SPU-side generic constraint solver easier.

Note: all build systems need to be updated: remove SpuVoronoiSimplexSolver.cpp, SpuGjkPairDetector.cpp, SpuEpaPenetrationDepthSolver.cpp, SpuGjkEpa2.cpp

src/BulletCollision/NarrowPhaseCollision/btConvexPenetrationDepthSolver.h

@@ -14,8 +14,8 @@ subject to the following restrictions:
 */
 
 
-#ifndef CONVEX_PENETRATION_DEPTH_H
-#define CONVEX_PENETRATION_DEPTH_H
+#ifndef __CONVEX_PENETRATION_DEPTH_H
+#define __CONVEX_PENETRATION_DEPTH_H
 
 class btStackAlloc;
 class btVector3;