* src/gpgme.h.in (GPGME_ENCRYPT_WANT_ADDRESS): New flag.
* src/engine-gpg.c (add_arg_recipient): New.
(add_arg_recipient_string): New.
(append_args_from_recipients): Call new helper function.
(append_args_from_recipients_string): Ditto.
* src/gpgme-json.c (op_encrypt): Add flag "want-address".