Implement DNSSEC resolving

And fix some other DNS resolving issues too:

  1. Your DNS resolver is unable to receive a large (>1500 byte) DNS response successfully, even though it advertises itself as EDNS-enabled.
  2. The resolver at (pdns32) could not process the following tested types: Medium (~1300B) TXT records, Large (~3000B) TXT records, Large (~3000B) TXT records fetched with EDNS0
  3. It does not wildcard NXDOMAIN errors.

I second the feature request for DNSSec.