o Major bugfixes (hidden service v3):
    - An intro point could try to send an INTRODUCE_ACK with a status code
      that it wasn't able to encode leading to a hard assert() of the relay.
      Fortunately, that specific code path can not be reached thus this issue
      can't be triggered. We've consolidated the ABI values into trunnel now.
      Fixes bug 30454; bugfix on 0.3.0.1-alpha.
    - HSv3 client will now be able to properly handle unknown status code from
      a INTRODUCE_ACK cell (nack) even if they do not know it. The NACK
      behavior will stay the same. This will allow us to extend status code if
      we want in the future without breaking the normal client behavior.