Write restart flags to restart services only when necessary

Write restart flags to restart services only when necessary

Write restart flag file for services managed by Pacemaker into
/var/lib/tripleo/pacemaker-restarts directory. The name of the file must
match the name of the clone resource defined in pacemaker. The
post-puppet restart script will restart each service having a restart
flag file and remove those files.

This approach focuses on $pacemaker_master only (we don't want to
restart the pacemaker services 3 times when we have 3 controllers), so
it relies on the assumption that we're making the matching config
changes across the pacemaker nodes.

Change-Id: I6369ab0c82dbf3c8f21043f8aa9ab810744ddc12