Updated docs

new doc generation. Lots of changed files, I have removed the duplicated assets from each version of the docs, they now all point to a central location.

* Added `active` class to current page in sidebar. Fixes #47
* Added index page to root of docs/ and each version root. Fixes #56
* Added 'Improve this doc' button and a link to the source file. Fixes #48 
* Added select version dropdown to jump between versions of docs. Fixes #49 

![screen shot 2014-05-18 at 00 20 46](https://cloud.githubusercontent.com/assets/2510520/3006268/04ceb7ec-de1a-11e3-9047-e8a0d0e1882f.png)