[cairo] Cairo XCB backend

[Carl Worth]

On Feb 2, Jamey Sharp wrote:
 > Cairo can use XCB as a backend in place of Xlib now, meaning we have a
 > new class of potential test apps for XCB. I've committed changes to
 > cairo, xcb-proto, and cairo-demo.

Jamey,

Thanks you very much for contributing this work! I'm looking forward
to playing with it at some point.

 > Cairo's XCB backend can't currently be compiled alongside the Xlib
 > backend, because both libraries define some of the same symbols. (I'd
 > really appreciate people's thoughts on making the libraries co-exist
 > better.) Meanwhile, I set Cairo's configure script to default to not
 > building the XCB backend.

Just to make sure I understand you. You are saying that there is not a
problem in cairo, but that XCB and Xlib cannot currently both be
linked into a single application, correct?

-Carl