(skip_token): New.
(_gpgme_verify_status_handler): Watch out for wrong key usage.
(gpgme_get_sig_string_attr): Hack to return info on the key
usage. Does now make use of the former RESERVED argument which
has been renamed to WHATIDX.
(gpgme_get_sig_ulong_attr): Renamed RESERVED to WHATIDX.
* gpgme.texi (Verify): Explain the new whatidx variable.