Bugfixes in the frontend and backend

Backend:
    Now correctly kills the scoreboard thread.
    However, it is not too bad to always have one running to send
    the final scoreboard too, with this you can see newly joined
    players.

Frontend:
    Merged in the snake factory to the grid controller, now
    words are correctly displayed as green or red when the response
    comes from the websocket

    The resize function has been simplified a bit