o Minor features:
    - Be more generous with how much bandwidth we'd use up (with
      accounting enabled) before entering "soft hibernation".
      Previously, we'd hibernate once we'd used up 95% of our allotment.
      Now, we use up 95% of our allotment, AND make sure that we have
      no more than 500MB/3 hours of traffic remaining before we enter
      soft hibernation.

  o Minor bugfixes:
    - For bandwidth accounting, calculate our expected bandwidth rate
      based on the time during which we were active and not in
      soft-hibernation during the last interval.  Previously, we were
      also considering the time spent in soft-hibernation.  If this
      was a long time, we would wind up underestimating our bandwidth
      by a lot, and skewing our wakeup time towards the start of the
      accounting interval.  Fixes bug 1789.  Bugfix on 0.0.9pre5.