Game Demo recording

#1 This code is probably gone with other Tribes2 stuff.

There's two ways to do it:

1) Log all input with a relative time stamp (ie, inputTime = currentTime - levelStartTime). Then, when you load the demo/input log, simply move a cursor along the timeline, treating the timestamped input events as real input.

2) Rather than the input itself, simply track the users orientation, position and status (firing weapon, etc.) each frame. When replaying, simply stream these values back in across frames.

To record an AVI, you can just take screenshots every frame and dump them to a single file. Serious framerate hit... but it can even be done offline by rendering to an offscreen surface instead.