Feature Request: last_seen field for hosts/services table in the MSF DB

[jimhranicky]

Would anyone find if helpful if the hosts/services table had a last_seen field? It seems like (I could be wrong) that hosts/services that are up for extended periods of time don't get updated regularly. We're using the db_nmap functionality to keep an inventory of hosts/services on our network, and it would be nice if runs of db_nmap/db_import could show that the host/service was still up as of the last run.