[ab] lispbuilder-sdl documentation update

[Luke J Crook]

Christopher Eineke wrote:
> 
> what parts of lispbuilder-sdl do you think need the most work right now?
> 

1) Tutorials; We need at least one.

2) Ellipses. Fast filled Trigons and Polygons.

3) Antialiasing; It would be great to have support for this.

4) Sprites; We need a sprite capability.

5) Collisions; Bounds collisions (circle/square) and pixel collisions.

6) Dirty Rects;

7) A second event model; I use WITH-EVENTS, but others prefer overriding
a mouse-moved method.

8) Backgrounds; For easy scrolly parallax type effects (Shadow of the
Beast etc.)

9) Profiling/Optimization

- Luke