* key.h (struct certsig_s): New. Use it in gpgme_key_s.

* key.h (struct certsig_s): New.  Use it in gpgme_key_s.
* key.c (gpgme_key_release): Release it. We need to add more code
of course.
(_gpgme_key_append_name): Use memset to intialize the struct.
* gpgme.h (GPGME_KEYLIST_MODE_SIGS): New.
* rungpg.c (_gpgme_gpg_op_keylist): Include sigs in listing depending
non the list mode.

* key.c (gpgme_key_get_string_attr): Use GPGME_ATTR_TYPE to return
information about the key type (PGP or X.509).
(gpgme_key_get_ulong_attr): Likewise.

* keylist.c (keylist_colon_handler): Include 1 in the check for
valid algorithms so that RSA is usable.  Store the issuer name and
serial number also for "crs" records.  Parse the expire date for
subkeys.
(set_userid_flags): Put them onto the last appended key.