[crossfire] Partial transparency

[Nicolas Weeger (Laposte)]

>   But poking in the gtk source code, it does appear it is relatively clever
> in its drawing logic, using shared memory and xrender extension, so
> performance may actually not be that bad.  It'd perhaps be interesting to
> convert the gtk draw code to use the gdkpixbufs instead of the gdkpixmaps
> and see how much a performance difference there is just for standard
> images, and then start throwing in some transparent images.

Let's just hope those tricks, if we use them, work under Windows & Mac & other 
platforms too :)

Nicolas