[plt-scheme] allegro.plt updated for 4xx

[Simon Michael]

> It might be nice to add this to the allegro.plt examples, and  
> publish the lot via darcs for easier collaboration. Any thoughts ?


Well, I tried it as an experiment and to record this morning's work:
http://joyful.com/darcsweb/darcsweb.cgi?r=allegro.plt;a=summary

This makes all examples run with PLT 4 and adds your pacman and  
raptor. It doesn't (yet) contain the large allegro and libpng source  
trees.

Thanks again, this package really seems to work pretty well.

-Simon