output status information during guest shutdown again

output status information during guest shutdown again

Since the move to systemd libvirt-guests doesn't output this progress
information anymore. This patch brings back this feature.

It is helpful to show the admin what the system is waiting for and what
is left of the timeout (e.g. for calibrating the shutdown timing of a ups).

Rewriting the current line with \r doesn't work anymore in the context
of systemd. So always write new lines, but move to 5 second intervals
to avoid flooding the console.