Filter and download data v0.2

**Open pull request. Do not merge.**

This is an initial push of a v0.2 filter and download data page. it moves our layout from this:

![screenshot 2014-11-05 22 49 19](https://cloud.githubusercontent.com/assets/4827522/4931448/b17fc8f6-6578-11e4-892a-fc724c2e8b52.png)

To this:
![screenshot 2014-11-05 22 42 21](https://cloud.githubusercontent.com/assets/4827522/4931416/32d80216-6578-11e4-8b2e-be398d2c4b04.png)

This layout is not entirely functional yet (ie, the switches have been removed that control the filtering, and some of my sketch details are not live yet). Need to work on live chart implementation.

This layout also attempts to address several of the usability issues with the dataset:
- some types of data are only available with certain combinations of commodities and revenue types. The previous layout pushed all information into one chart. This layout attempts to group commodities on first load. @nickbristow , the idea is that the chart would show stacked bars for the commodity groups shown on the right rather than displaying all the options at first (_not yet implemented, this layout still has the full chart at the moment_)
- not implemented yet: click-to-reveal/rollovers on the commodity groups would display drill-down options. Simplified mockup below, and more advanced implementation example [here](http://arcticspills.wwf.ca/#layers/oilgas/)
![screenshot 2014-11-05 23 09 36](https://cloud.githubusercontent.com/assets/4827522/4931582/8f44a6f0-657b-11e4-813d-5820c789fbb9.png)