[plt-scheme] Games and stuff for OSX

I solved the problems running mzscheme with Allegro on OSX and so the
1.4 planet package of allegro can be run on OSX( PPC ). Ill build an
intel osx port when I either figure out how to get the cross compiler or
find a friend who has an intel mac.

So to try it out type one of the following followed by (run)

(require (planet "wormhole.ss" ("kazzmir" "allegro.plt" 1 4) "examples"))
(require (planet "ex3d.ss" ("kazzmir" "allegro.plt" 1 4) "examples"))
(require (planet "exhello.ss" ("kazzmir" "allegro.plt" 1 4) "examples"))
(require (planet "exblend.ss" ("kazzmir" "allegro.plt" 1 4) "examples"))
(require (planet "piano.ss" ("kazzmir" "allegro.plt" 1 4) "examples"))
(require (planet "xquest.ss" ("kazzmir" "allegro.plt" 1 4) "examples/xquest"))

Its hard to keep the mouse inside the screen in the xquest game, so it may be fairly unplayable.
There are a few issues with the osx port:
1. Cannot goto fullscreen mode with 16 bit color depth. This is fixable.
2. Some colors are swapped. I think this is an endianness issue, probably fixable.
3. Interacting with the screen is slower than windows/linux. Maybe fixable.

if anyone tries this let me know any any issues you encounter. Thanks to Matthew for his help in solving the OSX problems.