[Xcb] Porting the rest of the X.Org apps to xcb

[Lev Babiev]

> At least at a quick glance, I think these could be fairly 
> straightforward to port to XCB, though whether it's worth the effort 
> for all of them is debatable:
>
>    backlight, ico, xcmsdb, xcompmgr, xdriinfo, xhost, xinit, xkill,

I took a stab at porting xhost to xcb, but it looks like some host 
family definitions are only available in Xau. With Krb5 currently 
disabled, there are no protocol requests to depend on; however, there 
are host family definitions such as FamilyLocalHost and FamilyNetname 
that are only defined in Xauth.h. Should these be included in 
xcb_family_t?

I also couldn't see any defition of server interpreted address structure 
in xcb. 

Cheers,
Lev