o Minor bugfixes (directory mirrors):
    - Allow relays to use directory mirrors without a DirPort: these relays
      need to be contacted over their ORPorts using a begindir connection.
      Fixes bug 20711; bugfix on 0.2.8.2-alpha.
    - Clarify the message logged when a remote relay is unexpectedly missing
      an ORPort or DirPort: users were confusing this with a local port.
      Fixes bug 20711; bugfix on 0.2.8.2-alpha.