progress_cb and progress_cb_arg.
(ccid_set_progress_cb): New.
(print_progress): New.
(ccid_transceive): Call print_progress for wait time extensions.
* apdu.c (struct reader_table_s): Add field set_progress_cb.
(new_reader_slot): Clear that field.
(open_ccid_reader): Set it to ..
(set_progress_cb_ccid_reader): ... new fucntion.
* app.c (print_progress_line): New.
(lock_reader): Add arg CTRL to set a progress callback and
change all callers to provide it.
(unlock_reader): Remove the progress callback.