Johannes Löthberg authored Jun 23, 2015 and Lukas Fleischer committed Jun 27, 2015

Also add an utility function for formatting the ForceCommand, using
shlex.quote to quote the value.

Signed-off-by: Johannes Löthberg <johannes@kyriasis.com>
Signed-off-by: Lukas Fleischer <lfleischer@archlinux.org>