One of dhcpcd's manpages (http://www.daemon-systems.org/man/dhcpcd-run-hooks.8.html)
says that user-defined hooks are supposed to go into /etc/dhcpcd.e[nter,exit]-hook, where
they can be much more tightly controlled.  This represents my first attempt at making use
of these scripts.

Signed-off-by: The Doctor <drwho@virtadpt.net>
Merge branch 'master' of https://github.com/Byzantium/Byzantium