* If a reboot stuck node fails, move the node to hwdown, send email,
  and log an entry in the nodelog. Then continue on.

* If os_load fails, record the nodes that failed, and try again if the
  nodes fail to reload at the retry interval. Do not exit. I was going
  to call os_load again immediately, but decided not to since these
  changes were quite easy.

  The above change not really tested ... waiting for os_load to fail!