This hardcodes a define, but other projects (wlc/weston) either use the raw
number or just redefine it with another name anyway...
This should fix travis build.
handle map/unmap_notify, property_notify (just logging for now), and
client_message for wl_surface_id.
We almost can display an X window now, just need the compositor to
iterate over them
Dominique Martinet