[Majiang] Bugs fix and SillyAgent complete

- Fix bug: canHu(card)
    [[5,1], [6,1], [7,2]] ---canHu(4)---> False
- Fix bug: canHu()
    [[31,3],[32,1],[33,1]] -------------> True
- Fix bug: after Peng, 'turn' is wrong
    #0 kick; #3 peng; #1 => #0
- Implement complete SillyAgent
    support randomly angang, chi, peng, gang
- Improve output format in cmdmj
- Remove class Game members
    def commonPick
    self.turn
    def next