gpg: New AKL method "ntds"
* dirmngr/ks-engine-ldap.c (keyspec_to_ldap_filter): Change the new support for KEYDB_SEARCH_MODE_MAIL. (ks_ldap_get): Add a debug. * g10/options.h (AKL_NTDS): New. * g10/keyserver.c (keyserver_import_ntds): New. (keyserver_get_chunk): Allow KEYDB_SEARCH_MODE_MAIL. * g10/getkey.c (parse_auto_key_locate): Support "ntds". (get_pubkey_byname): Ditto.