* Check keys on import?
   * Non self-signed user IDs
   * Non self-signed subkeys
   * Invalid revocations
   * Signatures marked as non-exportable
   * PKS subkey damage
* Better signature subpacket parsing (primary UID for example).
* Better merging of signatures; need to compare subpackets on Type 4 packets
  and choose which we should use (how? most recent date?)
* Honor no-modify keyserver flag ("Brian M. Carlson" <karlsson@hal-pc.org>)
* Better txt2html routine.
* Pathfinder - graphical as well?
* Do pathlengths for similar email addresses to help aide keysigning.
  (ie "Find me the keys furthest from mine that end ox.ac.uk'")
  Suggested by Jochen Voss <voss@mathematik.uni-kl.de>.
* Other stats. most signed? signs most?
* DB access modules as a library to allow runtime configuration of it?
* Clean up gcc warnings (`ll' length modifier especially! Also inline & wrong
  signedness for lo_read/write)
* Test library?
* Full email interface support (ADD, INDEX etc)
* More comments.
* Look at db2 backend - is it db2's fault? (Well, deadlock in that the library
  probably is...). Pull some of the DB3 stuff across for completeness.