Fix the bug of judging

Link to #36 
## Given players logged in.
![screen shot 2014-07-27 at 7 39 26 pm](https://cloud.githubusercontent.com/assets/806135/3715719/75986a26-15f2-11e4-89ab-76be47c6c7d1.png)

## In one round, player can only play one card
![screen shot 2014-07-27 at 7 39 39 pm](https://cloud.githubusercontent.com/assets/806135/3715720/7ad9617a-15f2-11e4-88ff-10362db18eb2.png)

## And judge can only judge once all players have played
![screen shot 2014-07-27 at 7 39 53 pm](https://cloud.githubusercontent.com/assets/806135/3715721/7fc3b53c-15f2-11e4-8bdd-882256e795b4.png)