New game (draft): multiplayer mastermind

Rules (subject to change):
    2-6 players

    Players take turns trying to guess a sequence of colors secrectly
    decided by the cube (colors do not repeat within the sequence).

    At the beginning of the games, the players must choose a level (1-6):
    this will be the length of the sequence to be guessed (of course, 1 or 2
    are pointless...)

    The active player taps a sequence (tap twice, so as to avoid "misclicks")
    in front of all the other players.  Once he's done, the cube blacks-out.
    The player then hides the cube, click once again to reveal the score to
    himself only.  Exact guesses are drawn in green, color-only (correct
    color, wrong position) are drawn in red.

    Now, the active player may (or may not) announce his score.  If he chooses
    to, he is not obliged to announce his real score: he may lie about it.
    The next player has to choose whether he believes him or not.

    If he does not believe him, the active player reveals his score on the
    cube to the next player.  Two cases:
    A) the player lied -> It is now the next players' turn.
    B) the player did not lie -> he plays again (but cannot chose to announce
       his score again that time).

    If the active player does not chose to announce his score, he hides his
    score by clicking once more and hands the cube to the next player.

    The first player to play the correct sequence wins and is greeted by a
    fanfare.

Signed-off-by: David Wagner <david@marvid.fr>