[cairo] Compile Mac OS X universal binary of cairo

[Vladimir Vukicevic]

Ryan Schmidt wrote:
> I had wanted to do it that way to support Mac OS X 10.3.9 on PowerPC 
> machines. But I'm not yet convinced that what I'm making now won't work 
> on 10.3.9 anyway. It's not like any of this software is linking with any 
> special 10.4-only libraries. I guess I'll see when I'm done whether it 
> runs on 10.3.9 or not. :-/

Core cairo and the quartz backend(s) should work fine on 10.3.9; I don't 
know about xlib/freetype/etc.

     - Vlad