Tests todo:

A - SERVFAIL - should return empty response, ra 0
A - NXDOMAIN - should return SOA
A - NOERROR - should return A record
            - or delegated NS record

Record delegated to self should return SOA record rather than NS delegation

Casing should match on question section, always.

Casing should match on other sections if a direct match? (not required, but efficient for compression pointers)
  - www.EXample.COm + example.com = EXample.COm
  - EXample.COm + www.example.com = www.EXample.COm
  - (this should be taken care of by compression pointer logic, once implemented)

Send malformed packets (both as queries and as answers):
  - bad question count, answer count, etc
  - bad rdata (too long, too short)
  - proper packets, truncated
  - randomly twiddled bits
  - forward compression pointers
  - compression pointers to wrong bits (throw error on non-ascii / unsafe chars)