Fixes a crash when the idle-inhibit example application is closed by the
compositor, instead of Ctr+C on the spawning terminal, by actualy
handling the close request.
Adds a client example for the idle-inhibit-unsable-v1 protocol.
The client creates a surface and requests an idle inhibitor.
On pointer BTN_LEFT the inhibitor is destroyed if it exists, or
recreated if it was destroyed before.
The surfaces colour is based on the idle-inhibit state.
Green if an inhibitor exists, yellow if it does not.
