SDL Console palette support and waitkey fix.

(yet another squashed commit)
- add palette support, needed when (and if) plush
uses 8 bit internally.
- fix waitkey, it must not block (!).
true color screen surface.

Due to palette handling, is no longer needed to force the screen
surface to 8 bit color depth.

Actually, it did not draw anything before :) Still investigating.
port to the new Palette API

and print FPS too at the exit.
use POSIX integral types to be (more) portable.
remove warnings

wherever (seems to be) is safe.
greater image