Get rid of some warnings, mainly unused parameters/variables.

Thanks sparkprime for the patch, see http://code.google.com/p/bullet/issues/detail?id=330

src/BulletDynamics/Vehicle/btRaycastVehicle.h

@@ -80,6 +80,7 @@ public:
 	///btActionInterface interface
 	virtual void updateAction( btCollisionWorld* collisionWorld, btScalar step)
 	{
+        (void) collisionWorld;
 		updateVehicle(step);
 	}