_.inherits provide 'extend' method to constructors

- allows Backbone-like class definitions
Allow attribute transforms to be provided on the prototype

- Allows for easier backbone-style view models
eg.
  MyModel = aeris.ViewModele.extend({
    attributeTransforms: {
      // ...
    }
  });
Expose aeris.maps.markercollections.MarkerCollection
grunt build: copy assets to build dir