* g10/mainproc.c (check_sig_and_print): Add failsafe check for PK.
Pass KEYBLOCK down do check_signatures_trust.  Protect existsing error
ocde in case the signature expired.
* g10/pkclist.c (is_in_sender_list): New.
(check_signatures_trust): Add args keyblock and pk.  Add new uid based
checking code.
* g10/test-stubs.c, g10/gpgv.c: Adjust stubs.