Move puavo-configure-client stuff to happen before /sbin/init
is called.  We can drop service restarts, and will get more
reliable boots.  Also, do wait for dbus to start before starting
up screen sessions (at least lightdm requires a working dbus).
Note that without moving the /etc/nsswitch.conf configuration
to happen before dbus starts up, dbus starts in a broken state
(it does not, and can not know anything about puavo-users).