+ Updated pygame.display.update() to release the GIL whilst doing things,
+ so other threads can do things whilst it's updating the screen.
+ Some comments to help Mac OSX people installing, and compiling pygame.
+ About bdist_mpkg in setup, and also fixed an exception message
+ to be nicer about requiring pyobjc.
[BUG] Fixed up pygame.mask.from_surface, got color key, and perpixel alpha