Mouselook improvements

Since this mod was intended as a demonstration of some NTT functionality, a few improvements have been made to the way mouselook works. Camera rotation is now based on framerate instead of timescale (which is really how it should have been from the start), and there is an additional mouse sensitivity command, which is poorly named now that I think of it because its actual purpose is to provide a way for gamepad users to adjust sensitivity, since /mousesens does nothing for them.