Add archive-project-volumes

This is a script which can be run by hand (or in a cron?) on
labstore1001.  It archives the orphan volumes listed by
manage-nfs-volumes-daemon in /srv/project/volumes-without-projects

This is an important part of us fully supporting deletion
of labs projects.  After this script runs it should be
possible to recreate a new project of the same name without
leaking data from the old project to the new one.

Change-Id: Ibbe74e14059b2b2d2880e7ad3a2fb6f4c560eab6