2.2.1 - 2015-08-05
  *** Bugs fixed:
    * extfile plugin - if the addresses/CNAMEs for a given extfile
      service_type are not listed in natural sort order in the configuration,
      extfile will update the wrong items (sorting bug).
    * rfc1035 zonefile reloading - Directory scanning (SIGUSR1, or automatic
      periodic scanning on a non-inotify system) would treat all zonefiles as
      changed and reload them all, without first filtering them on whether
      their stat() data had changed since the previous scan.  Not really a
      functional issue, but certainly wasteful and noisy.
    * HTTP monitoring - was not sending any User-Agent string, now sends
      "User-Agent: gdnsd-monitor"