Adding group page

![screen shot 2014-07-02 at 12 30 32 pm](https://cloud.githubusercontent.com/assets/2283680/3454011/a2bca99e-01cb-11e4-8fca-4916fcaef3cb.png)

@amitaibu In hindsight, I think it would be nicer to use node_view as a teaser in that case, instead of preparing the node values manually.