[cairo] glitz surface fixes

[Vladimir Vukicevic]

On 12/23/05, David Reveman <davidr at novell.com> wrote:
> looks ok, you can commit it.
>
> btw, I haven't had time to look at the glitz test suite yet but I think
> you mentioned that you added pbuffer surface support, right? It'd like
> to test normal offscreen drawables (FBO drawables) as well. pbuffers
> will probably be supported by glitz for some time but eventually they'll
> be phased out in favor of FBOs. Feel free to add support for this or
> I'll add it as soon as I have time to look at the test suite.

I'll take a look tonight; right now the test suite tries to create a
pbuffer, and if it fails, it uses a real window, with GLX at least. 
I'll add FBO as the first-choice option here and add some more env
variables to force the others.

    - Vlad