[SDL] 2D API evolution (SDL 1.3/2.0)

[Sam Lantinga]

> So, using a single four point 2D transforming blit call on the backend 
> level does seem like a good idea to me. It's clean, simple, does what 
> we need, and plugs trivially right into the relevant 3D APIs.

> Ok... This sounds too easy. What are we missing? ;-)

Implementation? :)
Adding a feature to the existing software blitters is a daunting prospect,
since the complexity increases exponentially.

	-Sam Lantinga, Senior Software Engineer, Blizzard Entertainment