- Document the source code better.

- Add support for NS names and IPs to pgsqldns-conf.

- Add support for wildcard DNS records.  Two options on doing this:

  - Make querying the domain return all records for that domain, insert
    them into an associative array indexed by prefix, and select the
    appropriate records from that.
    - This is much faster for the common case, but large domains could
      cause problems.
    - This would also let us do the "additional" records without
      additional SQL queries.
    - This could also let us micro-optimize repeated queries for the
      same domain by holding onto the data if it is still less old than
      some threshold (say one second).

  - Issue SQL queries for shorter and shorter pieces of the domain name
    prefixed with a "*", until something matches.
    - This is the simplest solution.
    - Also the most time consuming due to the latency in receiving the
      data from the necessary SQL queries.