[WIP] Refactored Editor Routes

No issue yet. This is a "what do you guys think" sort of PR.

- Moved `new` route into `editor` resource (`editor.new`)
- Moved the current editor controller, view, and route to `editor.edit`
- Added `editor.index`, which automatically transitions into `editor.new`
- Moved controllers, views, templates, and routes to match new router config. Also changed links to `editor` into `editor.new` and `editor.edit` as appropriate.
It wasn't working, it's just that common usage (i.e., by clicking a link within the Ember app) doesn't cause the model hook to be executed (http://emberjs.com/api/classes/Ember.Route.html#method_model) so the route already had a copy of the model.

You can trigger the failure by going straight to the URL--without a transition, the route will use the model hook to get its model and you can see the failure.