Implemented skipping set_trailer_sector command for Mifare Plus SL3 cards.
Version 1.7.1.1

+ Implemented new APIs:
  + /api/config/edrpou - provides a way for client to customize EDRPOU for a program session.
  + /api/purse/refill - allows client to change purse value
Version 1.7.1.4

+ Extended /api/config/edrpou api call interface.
+ /api/purse/refill api call has been moved to webapi.card module.
  webapi.purse module was no longer needed and thus has been removed.
+ Documentation for new api methods updated.
Version 1.7.3

+ Implemented new /api/card/options and extended /api/card/init command.