Keep track of the previous drift value and only report a new one if it has changed.  Not a big deal when updates are 12 hours apart, but if we shorten the interval, it will help keep gratuitous updates down.
Keep track of the previous drift value and only report a new one if it
has changed.  Not a big deal when updates are 12 hours apart, but if we
shorten the interval, it will help keep gratuitous updates down.

Put a timestamp in the log when watchdog starts.

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