=head2 moosesign

Does simple PGPMoose signing of messages.  This module is B<not> a full
implementation of PGPMoose; in particular, it doesn't support all of the
crosspost handling.  It looks through the groups in the Newsgroups header
and adds a PGPMoose X-Auth header for every group in the Newsgroups header
for which a PGP key has been given.

This module takes one configuration directive, which associates a PGP key
ID and passphrase with a newsgroup:

=over 4

=item pgpkey NEWSGROUP PASSPHRASE KEYID

Associates the given C<KEYID> and C<PASSPHRASE> with C<NEWSGROUP>.
C<KEYID> is optional and will default to the name of the newsgroup
surrounded by spaces if not given.  (This default will allow PGP to find
the key correctly if the key ID is something like "Moderator for
group.name <address>" while avoiding confusing group.name and
group.name.other.)

=back

Note that using this module means putting the PGP passphrases for the
moderation keys in cleartext in the configuration file or in the script.

This module takes no arguments and cannot fail.