[compiz] adding XCB dependency

[dragoran]

> Just for curiousity - which distros do actually ship XCB at the moment,
> at least as some sort of extra/unofficial package? I couldn't find one
> at the moment for my distro (FC6/F7) and I doubt many people (as in:
> users of compiz) want to compile XCB and Xlib/XCB manually.
> Does anyone of you know when XCB will be included in all major
> distributions? 
>
>   
for fedora its planned for F8 (ajax said this last time when somebody 
asked about it)