This commit includes a script to clean old idle data from the emulab
database (iddata_clean), and a script to generate fake idle entries for testing scripts on the minibed (idloadup.pl). iddata_clean, by default, removes all idle entries older than 36 hours. This can be changed by providing -m <maxage> (in seconds) to it. idloadup.pl adds random idle data at time offsets from now, to 5 days prior (1 sec granularity). It adds anywhere from 1 to 10 entries per PC to the node_idlestats page, and from 1 - 10 x # interfaces to the iface_counters table.