Merge ccid_driver_improvement branch.
* scd/apdu.c (ccid_keypad_operation): Rename from ccid_keypad_verify. (open_ccid_reader): Use ccid_keypad_operation for verify and modify. * scd/ccid-driver.c (VENDOR_VASCO, VASCO_920): New. (ccid_transceive_apdu_level): Permit sending packet where apdulen <= 289. Support receiving packets in a chain. (ccid_transceive_secure): Maximum is 15 for VASCO DIGIPASS 920. Support keypad_modify method such as CHANGE_REFERENCE_DATA: 0x24.