Isolated card_swipe so that it just gathers and decodes data from the magnetic card reader and calculates the length of the data.  This is so we can use it again for the original swipe the user will do when the device is reset to factory settings.  The original card data will be saved to flash memory so that we can verify whether or not the user has the real master keycard.  verify_card (similar to verify_pattern and verify_username) will take care of this.  Also, made enter_master_mode its own function, there was too much going on to keep in the main loop.  Anyway, I'm fading fast, I'll pick this up again tomorrow.