o Major feature (hidden service):
    - For a newly created hidden service, the default version is now 3. Tor
      still supports version 2 service but the operator now needs to
      specifically set "HiddenServiceVersion 2" in order to create a new
      service.

      For existing services, tor now learns the version by reading the key
      file so the HiddenServiceVersion is not mandatory in that case. Closes
      ticket 27215.