[Xcb] new library for pthread stub functions

[Barton C Massey]

In message <4564C9ED.7080009 at freedesktop.org> you wrote:
> Thus, we force every program to do something slightly
> different for the static and non-static case, and we don't
> have any way of expressing that in pkg-config.

Ah, that last was the part I was missing.  Sounds to me like
we should file a pkg-config bug.  On the other hand, would
your libtool replacement be able to do the right thing?

	Bart