Piston/PistonWindow changes broke fullscreening

[mason-larobina]

In the latest update I've disabled fullscreening (the F toggle) until the root cause and code fix is pushed.

I've tried several variations of window destruction / creation and unable to determine what is causing the crash. Piston gives very little control over the glutin internals (intentionally) and the crash is coming from the creation of multiple glutin event loops.

thread 'main' panicked at 'Creating EventLoop multiple times is not supported.