Aggregates time control and horizontal aggregates legend

This pull request adds a control for the number of hours to show for aggregates. It also includes some major cleanup of the loading code, and a redesigned aggregate scale to better fit alongside the control.

![screen shot 2014-10-02 at 12 17 49 pm](https://cloud.githubusercontent.com/assets/320910/4486118/8b06779c-49da-11e4-8694-85bfd91d9905.png)