Nicer button for stats Type

Replace button by tabs for statsType selection.
Also gives a better support in responsive.

Before : 
![before](https://f.cloud.github.com/assets/1484406/2491945/f06afc90-b207-11e3-8dcd-d800417741cb.png)
![before-responsive](https://f.cloud.github.com/assets/1484406/2491947/09b37da8-b208-11e3-8731-77842c7a9ef9.png)

After : 
![after](https://f.cloud.github.com/assets/1484406/2491952/480ba742-b208-11e3-828f-835175448b8a.png)
![after-responsive](https://f.cloud.github.com/assets/1484406/2491950/243d838a-b208-11e3-8075-484ad5616ef8.png)