Rename Smardown module, first rough attempt at making visualisation work

Rename Smartdown module to avoid module name clashes. 
Rough implementation of GraphPresenter: the nodes are visible, and flow is correct but rules are poorly styled. 
The implementation for NestedRule is hacky at best. 

The result as of commit 6a651b6 is:
![screen shot 2014-08-07 at 18 05 49](https://cloud.githubusercontent.com/assets/5455804/3845693/464d4b7c-1e55-11e4-84ac-74c0efc8f0ec.png)