Updates the start_time and end_time fields in widearea_recent.
Updates the start_time and end_time fields in widearea_recent.

Also, changed the way that bandwidths were being looked up in
the widearea_delays, to make it work better if nodes' IP addresses
change.

nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome