[WIP] Statistics design

We create a more readable page for stats. At the moment, it's basic. But we prefer be sure to do it well.
I dont' know for others pods, but framasphere's users like check stats :) 

![statistics_preview](https://cloud.githubusercontent.com/assets/6507951/5342745/aa8ac676-7f00-11e4-9799-c4f4c3e8752c.png)

Since this page is targeted at the ordinary user, we should be a little bit more explanatory here I think, something like "Posts can be published to:" maybe? And then maybe just list the available ones out, hiding this altogether if none are enabled.