TODO

* Remove references to TAT

  TAT was an internal, java-based test framework that is no longer in
  use.  Instead this code is generally just invoked directly from the
  command line.  Results are generally determined from the log output.

* Implement some form of parallelism.

  A common use case for this tool is to give it a (possibly long) list
  of queries to do.  Right now, it will just process them serially.
  However, with some parallelism, we should be able to go faster.

* Complete CNAME response validation code (in progress).

  In the unbound-prototype, we split the CNAME chain and then
  requeried for each element of the chain.  This would allow us to
  re-determine the chain of trust for each element.  In this code,
  however, since we don't have a facility (nor want one) to establish
  chains of trust, we are going to try and validate the response in
  one pass.  Note that we have to account for wildcard CNAME
  expressions, as well as validate the end-of-chain.