implemented background polygon FusionTablesLayer

@JackDougherty ok got the background polygons working!

![screen shot 2014-03-13 at 11 23 02 am](https://f.cloud.github.com/assets/919583/2411812/cd30a768-aacb-11e3-9c01-b534632ce27c.png)

![screen shot 2014-03-13 at 11 23 11 am](https://f.cloud.github.com/assets/919583/2411813/d0481da0-aacb-11e3-92ab-63fab93d7ac1.png)

You were pretty close with getting it working yourself. A few notes:
* You were defining your FusionTablesLayers properly, but the logic to display them was not quite right. I moved the logic in to the `doSearch` function so they update whenever a checkbox or radio button is changed.
* The `styleId` and `templateId` parameters are necessary to get your customized styling and info windows. Otherwise, they will render by default as red polygons.
* You may want to make your polygon layers a bit more transparent to make the point data stand out a little bit. Also, I pushed up a separate commit to desaturate (basically make greyscale) the base Google Map. I've found it helps when displaying polygon data to keep the color pallets from conflicting.

Let me know if you have any questions!