- Make configurable options specifiable on the command line (idle
   time, packets/hour, "freshness" time).
 - Check how fresh our data is, and mark it as stale if it is old.
 - Add display options. Default is show only inactive, swappable, non-stale.
   Use -s flag to show stale expts too, and -u flag to show unswappable
   ones. (-s and -u display whether they're active or not)
 - Changes in the database optimized the queries for me, so instead of
   taking 10-15 seconds to run, it now takes 1.
See usage (idlecheck -h) for more info.
We're now ready to put this in a cron job and in idle view of the expt
listing web page.