Add Model listeners

I'm really excited to add "Model Listeners" to the Inspector. Being able to see at a glance which other objects are listening to a model will indicate how models relate to one another and relate to views. In the Todo app every todo item model has a todo itemView that observes it's changes. This will be true and more so for our more interesting apps. Furthermore, when there are memory managment issues, events will remain bound when they should be unbound. 

![](http://f.cl.ly/items/0a0w1D2s3i2s3L1j2A0D/Image%202014-11-20%20at%206.40.42%20PM.png)

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sidenote:

So, i'm probably a victim of aggressive code cleanup as I go. One of the common refactorings I'm pushing through with these changes is an iife change. where functions that were previously defined on the agent scope are now inside a closure. The benefit is that their helper functions and state are hidden, but the change is hard on the eyes, so i'm sorry about that. 
I love how easy it is to add a new source of data and update that field on the fly. We could probably generalize this pattern to any type of data given `attributes` and `events` changes are so similar