Minor fix in friction: calculate second friction direction based on un-scaling first friction direction (issue if it was scaled to zero)

Force activation state of static objects to be ISLAND_SLEEPING, once they are added to the world
Add backwards compatibility option btDiscreteDynamicsWorld::setSynchronizeAllMotionStates, just in case only updating active objects broke someones code
Don't disable 3D box-box in box2ddemo

src/BulletDynamics/Dynamics/btDiscreteDynamicsWorld.h

@@ -52,6 +52,7 @@ protected:
 
 	bool	m_ownsIslandManager;
 	bool	m_ownsConstraintSolver;
+	bool	m_synchronizeAllMotionStates;
 
 	btAlignedObjectArray<btActionInterface*>	m_actions;
 	
@@ -177,6 +178,15 @@ public:
 	///obsolete, use removeAction instead
 	virtual void	removeCharacter(btActionInterface* character);
 
+	void	setSynchronizeAllMotionStates(bool synchronizeAll)
+	{
+		m_synchronizeAllMotionStates = synchronizeAll;
+	}
+	bool getSynchronizeAllMotionStates() const
+	{
+		return m_synchronizeAllMotionStates;
+	}
+
 };
 
 #endif //BT_DISCRETE_DYNAMICS_WORLD_H