* dirmngr/server.c (cmd_ks_get): Add option --newer.
(cmd_ad_query): Ditto.
* dirmngr/ldap-misc.c (isotime2rfc4517): New.
(rfc4517toisotime): New.
* dirmngr/ks-action.c (ks_action_get): Add arg newer and pass on.
(ks_action_query): Ditto.
* dirmngr/ks-engine-ldap.c (extract_keys): Print new "chg" record.
(ks_ldap_get): Add arg newer. Modify filter with newer arg.
(ks_ldap_search): Print the modifyTimestamp.
(ks_ldap_query): Add arg newer. Modify filter with newer arg.
--
Note that the modifyTimestamp is also available on Windows, where its
value is more commonly known as whenChanged. Both are constructed
attributes.
Note that the --newer option is a bit of a misnomer because LDAP has
only a greater-or-equal and no greater-than operator.
(cherry picked from commit 56d309133f0e54ac5e2f95871fb74f8cb97e2636)