o Removed code:
    - The internal pure-C tor-fw-helper tool is now removed from the
      Tor distribution, in favor of the pure-Go clone available from
      https://github.com/Yawning/tor-fw-helper .  The libraries used
      by the C tor-fw-helper are not, in our opinion, very confidence-
      inspiring in their secure-proggramming techniques. Closes ticket 13338.