* Check revocation and expire stuff.

    * Check calculation of key validity.

    * preferences of hash algorithms are not yet used.

    * Check Berkeley BD - it is in glibc - any licensing problems?

    * I noticed, that we sometimes have only 3 items in a trustrecord, but
      a next pointer ro more records - check wehther the reuse code really
      works. Maybe this is the reason for the "Hmmm public key lost"

    * clearsig: keep lineendings as they are. Remember that trailings
      blanks are not hashed.

    * OpenBSD: dynamic loading with dlopen works on OpenBSD, but:
      OpenBSD binaries are a.out, so every symbol begins with "_"

    * should we flush the getkey.c caches while doing an import?

    * The critical bit of signature subpackets is not yet supported; i.e.
      it is ignored.

    * We need a maintainence pass over the trustdb which flags
      signatures as expired if the key used to make the signature has
      expired.	Maybe it is a good idea to store the exiration time
      in the key record of the trustdb.

    * write a tool to extract selected keys from a file.

    * new menu to delete signatures and list signature in menu

    * Replace the SIGUSR1 stuff by semaphores to avoid loss of a signal.

    * add test cases for invalid data (scrambled armor or other random data)

    * rewrite --list-packets or put it into another tool.

    * Burn the buffers used by fopen(), or use read(2). Does this
      really make sense?

    * Change the buffering to a mbuf like scheme? Need it for PSST anyway;
      see Michael's proposal.
    * add checking of armor trailers
    * remove all "Fixmes" ;-)

    * add an option to re-create a public key from a secret key; we
      can do this in trustdb.c:verify_own_keys.
      (special tool?)

    * change the fake_data stuff to mpi_set_opaque

    * Add some stuff for DU cc

    * Use "user ID", "trustdb", "NOTE" and "WARNING".

    * Replace Blowfish by Twofish

    * Print a warning when a experimental algorithm is used.

    * Remove ElGamal signatures.