[ab] lispbuilder-sdl API changes

[Luke Crook]

Justin Heyes-Jones <justinhj at ...> writes:

> My only concern would be that you can still access the cffi
> layer from the topmost layer.

Yes, the CFFI bindings can be accessed directly using e.g. sdl-cffi::sdl-blit-
surface. The middle layer can be accessed using e.g. sdl-base::blit-surface. 

> 
> Sounds good though, let me know if I can help, perhaps with rewriting
> samples etc.

Hopefully I'll have finished the API work by Sunday. Then perhaps we can 
convert a few examples each.

- Luke