Use real data with scatter plot

This updates the scatter plot to pull in actual data from CartoDB, and switches to a log scale for better data visualization. Also adds tooltips and coloring.
![screenshot from 2014-12-03 12 24 14](https://cloud.githubusercontent.com/assets/447977/5285108/5479acb0-7ae7-11e4-8432-cfdb1f44bcdd.png)