No password needed for LAN

(its been tested for 1.3 but this will have it too I believe) The launcher in school is pretty old, and they can't update it easily as proxy blocks it. If you put in Notch in username and no password, and press play offline, you can log as Notch into game...So if MCGods its my trusted person with ability to be in creative when they want...someone could 'double-log' and he will be able to give diamonds, spawners to himself via the other 'user' (This only works with LAN worlds)