Filter marketplace

https://trello.com/c/J74qWDAb/46-filter-marketplace

![image](https://cloud.githubusercontent.com/assets/8669803/5109421/16133c9c-6fdf-11e4-9fe3-b57ea80a7d58.png)

![image](https://cloud.githubusercontent.com/assets/8669803/5109437/2aa39616-6fdf-11e4-8532-66f82215569b.png)

![image](https://cloud.githubusercontent.com/assets/8669803/5109444/33515be0-6fdf-11e4-893c-caead45fc55b.png)
might be better do sql things in listing model