[Xcb] Setting the WM_TRANSIENT_FOR property on a window

[Arnaud Fontaine]

Hi,

Thanks guy  for the  review. I  will push the  patch tomorrow  if nobody
complains before.

Besides of  these patches, I  have also attached  to this email  a patch
adding WM_COLORMAP_WINDOWS atom (I know  that the new type definition is
a bit ugly but this will  be merged with xcb-util/ewmh soon), in case it
could be useful to anyone.

I will push all these patches tomorrow I think.

Cheers,
Arnaud