added a `raw` button to view source code with no formatting

* opens up in a new window

![screen shot 2014-03-13 at 10 19 08 am](https://f.cloud.github.com/assets/13985/2404509/c343e1f0-aa3c-11e3-801b-68eed6275936.png)

once clicked a popup/new tab is opened with body looking like;

![screen shot 2014-03-13 at 10 19 43 am](https://f.cloud.github.com/assets/13985/2404512/dc51e3e0-aa3c-11e3-9329-027251688d7c.png)