0.2.0:
 - Fix occassional TCP connection leak in gethostbyname()
 - Fix TCP connection leak in recursive lookups
 - Remove deprecated use of Deferred.setTimeout
 - Improved test coverage for zone transfers
0.1.0:
 - Fix TCP connection leak in zone transfers
 - Handle empty or missing resolv.conf as if 127.0.0.1 was specified
 - Don't use blocking kernel entropy sources
 - Retry logic now properly tries all specified servers.
