Add a default logfile to manage-nfs-volumes-daemon.

Because it's good to have a log.

Change-Id: I2996a0959a57e538f5d824a7e7eed17d77786b66
Store a list of orphaned project volumes for later cleanup.

Change-Id: If3cf8cc2524c4e25df4f3eb8b40a12a216379584