* cardglue.c (open_card): Use shutdown code if possible.
(check_card_serialno): Ditto.
* ccid-driver.c (do_close_reader): Factored some code out from ...
(ccid_close_reader): ..here.
(ccid_shutdown_reader): New.
* apdu.c (apdu_shutdown_reader): New.
(shutdown_ccid_reader): New.