o Minor bugfixes:
    - Tolerate skew in stored vs computed interval starts for bandwidth
      accounting.  Now, if we change our configuration so that the start
      of the period changes by no more than 50% of the period's duration,
      we remember bytes that we transferred in the old one.  The upshot
      of this is that daylight savings time should no longer mess up
      bandwidth accounting and make each period potentially happen
      twice.  Fixes bug 1511; bugfix on 0.0.9pre5.