(cmd_encrypt): Add all enrypt-to marked certs to the list.
* encrypt.c (gpgsm_encrypt): Check that real recipients are
available.
* gpgsm.c (main): Make the --encrypt-to and --no-encrypt-to
options work. Pass the list of recients to gpgsm_server.
* gpgsm.h (certlist_s): Add field IS_ENCRYPT_TO.
(opt): Add NO_ENCRYPT_TO.
* certlist.c (gpgsm_add_to_certlist): New arg IS_ENCRYPT_TO.
Changed all callers and ignore duplicate entries.
(is_cert_in_certlist): New.
(gpgsm_add_cert_to_certlist): New.