[Proof of concept / do not merge] Basic pdf viewer

Starts to implement #98 

Though there are some unsolved design and interaction problems that need to be addressed. It is looking like this may get pushed for further work and not make this project deadline.
#### bd819xz1063
![screen shot 2014-10-22 at 11 30 26 am](https://cloud.githubusercontent.com/assets/1656824/4741908/c7c179ac-5a1a-11e4-84b6-876b9f885976.png)