[Xcb] making the icccm functions async

[Vincent Torri]

Hello,

I would like to make the icccm related functions asyc. These functions 
are:

xcb_get_wm_name
xcb_get_wm_icon_name
xcb_get_wm_client_machine

xcb_get_wm_size_hints
xcb_get_wm_normal_hints
xcb_get_wm_hints
xcb_get_wm_protocols

So I would like to add cookies and replies types.

The 3 first functions can obviously use the same cookie and reply type 
names.
The 5th function is using the 4th
In the last function, there is even a round trip as an atom is created.

So I would like to have your opinions about all thoses names, the 
functions to add or rename, etc...

Thank you

Vincent