Add scatter over time chart and use CartoDB data

![scatter-over-time](https://cloud.githubusercontent.com/assets/6386/5265147/4599a42c-7a0e-11e4-8481-0bfea4a3c4d2.png)

Consider removing Promise from the method name (I haven't ever seen this done in js code) and instead just adding a proper jsdoc string that has:
@return jQuery.Deferred object
in it.