Refactor smartdown adapter

Visualisers: 

HTML:
![screen shot 2014-08-19 at 21 12 26](https://cloud.githubusercontent.com/assets/5455804/3972441/7275a118-27dd-11e4-8af0-89d67bcfaf21.png)

Graphviz:
![animal-example-graphviz](https://cloud.githubusercontent.com/assets/5455804/3972437/6f91064a-27dd-11e4-8eb3-c2f0ed877474.png)