* scd/app.c (card_list_lock): Use MRSW lock.
(lock_r_card_list, unlock_r_card_list): New.
(lock_w_card_list, unlock_w_card_list): New.
(app_dump_state, app_send_devinfo): Use the MRSW lock.
(select_application, app_switch_current_card): Likewise.
(scd_update_reader_status_file): Likewise.
(initialize_module_command, send_card_and_app_list): Likewise.
(app_do_with_keygrip, app_wait): Likewise.