o Minor bugfixes (directory authorities, voting):
    - Add a new consensus method (31) to support any future changes that
      authorities decide to make to the value of bwweightscale or
      maxunmeasuredbw. Previously, there was a bug that prevented the
      authorities from parsing these consensus parameters correctly under
      most circumstances.
      Fixes bug 19011; bugfix on 0.2.2.10-alpha.