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)