Minor fixes (#ifndef SPU_COLLISION_OBJECT_WRAPPER_H block etc)
Only update 'setNumTasks' when necessary
Revert vectormath.h include (can't resolve conflicts with PS3 SDK, need additional #include path)
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