adding to resolver a way to lookup in namespaces (global variables)

Hi guys,

I am new in ember but to keep `reusable` code I wanted to create namespaces as described here https://github.com/emberjs/ember.js/issues/683.

One problems is no 'introspection' is done in that namespaces and I should create statemanagers or something like this.

My goal is to load a js file with a namespace and have all available like in an application object.

http://stackoverflow.com/questions/14488713/ember-namespaces-creating-reusable-apps

So I just edited resolverFor method to allow this, maybe in a future could be useful for plugable widgets, views or something like those.

BTW.- you are awesome really this is a wonderful project.