doing lots of resolutions and you are using a cache, switching
to the LRUCache is recommended.
+ dns.resolver.query() will try TCP if a UDP response is
+ truncated.
+
The python socket module's DNS methods can be now be overriden
with implementations that use dnspython's resolver.
Old DNSSEC types KEY, NXT, and SIG have been removed.
+ Whitespace is allowed in SSHFP fingerprints.
+
+ Origin checking in dns.zone.from_xfr() can be disabled.
+
+ Trailing junk checking can be disabled.
+
Bugs fixed since 1.9.4:
IPv4 and IPv6 address processing is now stricter.