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/BulletMultiThreaded/SpuNarrowPhaseCollisionTask/SpuConvexPenetrationDepthSolver.h

@@ -15,8 +15,8 @@ subject to the following restrictions:
 */
 
 
-#ifndef CONVEX_PENETRATION_DEPTH_H
-#define CONVEX_PENETRATION_DEPTH_H
+#ifndef SPU_CONVEX_PENETRATION_DEPTH_H
+#define SPU_CONVEX_PENETRATION_DEPTH_H
 
 
 
@@ -47,5 +47,5 @@ public:
 
 
 
-#endif //CONVEX_PENETRATION_DEPTH_H
+#endif //SPU_CONVEX_PENETRATION_DEPTH_H