Avatar's arm follows real or simulated Leap glove, if present.
This is a tiny change, and the effect is pretty good.
It's only active if there's a Leap device connected and you're using it, or else if you've used the Debug menu item to fake a Leap glove.
Merge pull request #695 from machinelevel/dev4

Avatar's arm follows real or simulated Leap glove, if present.