Sim demo

Changed sampling rate to 50 Hz, added the demo script, and added the logic for the recorder (it is mostly working -- still a few kinks to work out).
It's to account for how we treated it in Midas. For some reason, we have the yaw negated in Midas. I think it was an earlier hack to flip the direction of the mouse movement because we noticed it was moving in the opposite direction we expected. We should probably go back and see why that is. In the meantime, this makes the simulator agree with Midas. Otherwise, the mouse moves in the opposite direction you expect when the data is sent to Midas.