refactored GetBit and related funcs to be GetBitUInt8 since that's the context in which they are most often used.
Fixed warnings from display.c
Fixed warnings in demos.c
Fixed warnings in gameoflife.c. See line 19 for example of casting to pointers from integers. I need to convert this whole dang codebase to using portable types soon...
Fixed warnings in menu.c
Fixed warnings in memviewer.c
Fixed warnings in invaders.c
Fixed warnings in gfx.c
Fixed warnings in print.c (sans warnings about functions defined but not used)
Fixed warnings in input.c