[ann] zziplib sdl_rwops example

As there were questions how to easily get to use the zziplib
in an sdl-based game, I’ve done an example implementation of
an SDL_rwops interface. Use freely, and please report any
problems that are left. Thanks, and good luck.

… the project link …
… and a very short intro …

have fun,
– guido Edel sei der Mensch, hilfreich und gut
GCS/E/S/P C++$++++ ULHS L++w- N++@ d(±) s+a- r+@>+++ y++ 5++X- (geekcode)