Spike client side fetch js source

An initial spike on an idea for displaying source code within error/failure output.

![screen shot 2014-08-13 at 22 01 46](https://cloud.githubusercontent.com/assets/104158/3905647/65218b64-22ea-11e4-8bd9-6d4bc9ba9867.png)

![screen shot 2014-08-14 at 08 18 18](https://cloud.githubusercontent.com/assets/104158/3914025/2f5ee4c6-2340-11e4-8bdb-eda896272e45.png)

There seems to be a bit of repetition across the various reporter views. It would be good to at least not introduce more duplication. And maybe tackle reducing some of the duplication if it makes things obviously simpler.