[Xcb] api documentation with doxygen

[Vincent Torri]

Hello,

i've just made a first attempt of api documentation in xcb-util with
doxygen. I have documented only 2 functions. You can see the result here:

http://www.iecn.u-nancy.fr/~torri/files/xcb/doc/html/

do you think it is worth continuing documenting xcb-util ?

I have also xslt files that could give you gtk documentation style, if you
don't like doxygen output (like me ;) )

Vincent