Auto-hiding/shwing of the HUD. Added generation duplication detection.

Added autohiding of HUD during playback.
No UI to toggle auto-hiding yet.
Added generation duplication detection.
Merge branch 'master' of https://github.com/gregoryklein/GameOfLife

Conflicts:
	GameOfLife/GLGeneralHud.h
	GameOfLife/GLGeneralHud.m
	GameOfLife/GLTileNode.m