Inspired by X.org commit:

 commit 55c2e1a3aa587c58a74066724e11e30b3df267b8
 Author: Keith Packard <keithp@keithp.com>
 Date:   Mon Dec 7 15:11:33 2015 -0800

    xnest: Use SetNotifyFd to receive events
Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>