another large series of changes, related to the refactoring.

CompoundShapes are tricky to manage with respect to persistent contact points and swapped order of btCollisionObjects,
During dispatch, finding an algorith etc. order can be swapped.
fixed several other issues, related to SimpleBroadphase (removing a proxy was not working)

src/BulletDynamics/Dynamics/btDiscreteDynamicsWorld.h

@@ -43,6 +43,8 @@ protected:
 
 	btIDebugDraw*	m_debugDrawer;
 
+	btVector3	m_gravity;
+
 	bool	m_ownsIslandManager;
 	bool	m_ownsConstraintSolver;
 
@@ -65,6 +67,13 @@ protected:
 	void	updateVehicles(float timeStep);
 
 	void	startProfiling(float timeStep);
+
+	virtual void	internalSingleStepSimulation( float timeStep);
+
+	void	synchronizeMotionStates();
+
+	void	saveKinematicState(float timeStep);
+
 public:
 
 
@@ -76,7 +85,7 @@ public:
 		
 	virtual ~btDiscreteDynamicsWorld();
 		
-	virtual void	stepSimulation( float timeStep);
+	virtual void	stepSimulation( float timeStep, int numSubsteps=1);
 
 	virtual void	updateAabbs();
 
@@ -113,6 +122,10 @@ public:
 		return m_debugDrawer;
 	}
 
+	virtual void	setGravity(const btVector3& gravity);
+
+	virtual void	addRigidBody(btRigidBody* body);
+
 };
 
 #endif //BT_DISCRETE_DYNAMICS_WORLD_H