o Minor bugfixes (path selection):
    - When selecting relays by bandwidth, avoid a rounding error that
      could sometimes cause load to be imbalanced incorrectly. Previously,
      we would always round upwards; now, we round towards the nearest
      integer.  This had the biggest effect when a relay's weight adjustments
      should have given it weight 0, but it got weight 1 instead.
      Fixes bug 23318; bugfix on 0.2.4.3-alpha.
    - When calculating the fraction of nodes that have descriptors, and all
      all nodes in the network have zero bandwidths, count the number of nodes
      instead.
      Fixes bug 23318; bugfix on 0.2.4.10-alpha.