* Check if an object (a message, detached sign, public key, or whatever)
    is signed by definite user, i.e. define user
    (userid, or any other unique identification) on command line.

    * Change the internal represention of keyid into a struct which
      can also hold the localid and extend the localid to hold information
      of the subkey number because two subkeys may have the same keyid.

    * signature verification is done duplicated on import: in import.c and
      tehn in trustdb.c too.  Maybe we can use a flag to skip the actual
      verification process (this should work if we use the same keyblock,
      but I'm not sure how to accomplish that).  Another way is to allow
      the import of bogus data and let trustdb mark these keys as invalid;
      I see an advantage in this that it may help to prevent a DoS on a
      keyserver by sending him a lot of bogus signatures which he has
      to check - Needs further investigation.

  * abstraction of the MPI

  * Add a way to override the current cipher/md implementations
    by others (using extensions)

  * Not GnuPG replated:  What about option completion in bash?
    Can "--dump-options" be used for this or should we place the
    options in a special ELF segment?