add checkbox to filter password games

Add a little checkbox, that hide games with password

before:
![image](https://cloud.githubusercontent.com/assets/1217999/4801569/7ada4942-5e35-11e4-9c96-81afa3191c77.png)

after:
![image](https://cloud.githubusercontent.com/assets/1217999/4801573/83e31fd2-5e35-11e4-972d-aa02050e35b4.png)


TODO:
* filter coop games if you hide pw games and then active them
(Tester TLO was not able to host coop games)