[plt-scheme] Allegro 2.0

Allegro 2.0 has been released to planet. The main changes to this 
package are better documentation( HTML ), a more rigid game framework, 
and convenient translucency functions.

* The documentation is here: 
http://www.rafkind.com/jon/allegro-scheme/docs/2/0/allegro.html. It is 
also viewable from the Help-Desk by looking at the manuals link under 
Software.
* In the game framework I changed all classes from foo% to Foo
* Most primitive drawing functions have an associated /translucent and 
-screen/translucent which draw the primitive using an alpha channel. 
Example: (line/translucent some-image 0 0 0 128 20 20 100 100 (color 255 
255 255)).

I'm also trying to start a community of sorts, or at least a repository 
of games, that people can contribute to. So far there are only the 3 
games I wrote, simple.ss - xquest, pong.ss - pong, and raptor.ss - a 
remake of raptor: call of the shadows. There are other people writing 
games( not many ), so hopefully the game count will go up as time goes 
on. If you load any of them into drscheme they should "just work".

See here: http://www.rafkind.com/jon/allegro-scheme/