Two small fixes for FlixelNape:

I'm fix a bit a pull request of ProG4mr

- Fix for PostUpdate() no longer exists.
- Nape debug graphics were being draw on drawDebug cycle of flixel, which forces to use and see flixel debug to see nape debug graphics  ( please nooooo ).

Conflicts:
	src/org/flixel/nape/FlxPhysSprite.hx