initially we just change the default key
UNTESTED: application creation and minor refacorings
return nil as the value if there is an error
fix some issues
UNTESTED: setting application keys
fails at Changing static UID reading key
some code to revert card back to clean state when we have fscked up
tried to change order of key changes but still getting "unknown error", which most likely is actually authentication error (due to old libfreefare not setting errno correctly on authentication erorrs
Merge branch 'master' of https://github.com/rambo/nfc_lock