Don't panic link if the avatar is flying around
Reintroduce a fun hack

Yeah, looks like PhysX 2.6.4 has a bug with spawning stuff inside of
regions. So, let's bring back the hack that spawns the avatar at -2000
feet. The link-in process will set the correct position on the controller
and fire the appropriate detectors.
Bump the step offset by a tenth of a foot.

This should keep the avatar from getting stuck on some stupid stuff such
as on the pellet machine. A real fix would be to tweak the data, but we
cannot do that.
Merge pull request #296 from Hoikas/detectors

Some Physics Tweaks
Add functions to save/load the avatar to/from a file
Add avatar saving/loading to pfPython