Create the model pane 


This PR adds content to the "Data" pane and normalizes a bunch of the serializing logic in the agent. It's a  fairly hefty PR (31 files touched, 400 lines added, 200 removed). With that said, there are only a few places that are actually interesting. I'll point them out in the comments.

![](http://f.cl.ly/items/0y1S1K3Q1z0d0n1K3C1g/Image%202014-11-03%20at%201.13.32%20PM.png)

Commenting out log line is a general trend. We're mostly doing this because these tools have become fairly stable and it's easy to uncomment them when we want them on. This is obviously easier to do with Logger, which has support for bucketing logs by key and turning on the entire key... [Logger](https://github.com/MarionetteLabs/marionette.inspector/blob/master/extension/js/common/util/Logger.js)