[FEATURE Beta] New error stack trace

Given this code:

```javascript
export default Ember.Route.extend({
  model: function() {
    return [];
  },
  setupController: function IndexRouteSetupController() {
    throw new Error('Y U SO BROKE');
  }
});
```

Old stack trace:

![app 2013-12-06 14-43-17](https://f.cloud.github.com/assets/1131196/1695253/a88c7e78-5eae-11e3-8ed7-8c40b5e53326.jpg)

New stack trace:
![app 2013-12-06 14-41-56](https://f.cloud.github.com/assets/1131196/1695234/7783ca02-5eae-11e3-9c8b-ca5bafcd115b.jpg)

New stack trace points you to the exact line in your code (ES6 module) which caused an error to occur.

/cc @machty @rjackson