- added linear limits to btGeneric6DofConstraint and made sure the linear axis are in local space of objectA

- use microseconds instead of milliseconds for deltatime

Demos/CcdPhysicsDemo/CcdPhysicsDemo.cpp

@@ -160,7 +160,7 @@ void CcdPhysicsDemo::clientMoveAndDisplay()
 
 #endif //USE_KINEMATIC_GROUND
 
-	float dt = m_clock.getTimeMilliseconds() * 0.001f;
+	float dt = m_clock.getTimeMicroseconds() * 0.000001f;
 	m_clock.reset();
 	printf("dt = %f: ",dt);