* cardglue.c (open_card): Ask for card insertion.
(check_card_serialno): New.
(agent_scd_pksign, agent_scd_pkdecrypt): Use it here.
* cardglue.c (open_card): Issue insertion status message.
* status.h, status.c (STATUS_CARDCTRL): New.
* status.c (cpr_get_answer_okay_cancel): New.
* miscutil.c (answer_is_okay_cancel): New.