Upgrading Marionette to 1.3.0
Removing poor style external event trigger to EventFeed.
Renaming helper function.
Separating fileTree from controller navigation logic.
Decoupling events further.
Minor tidying of app events.
Moving contoller to separate file.
Moving showDeleted to be controlled by MainController.
Shifting logic out of AppLayout.
Moving remaining orchestration logic out of AppLayout.
Handling fileTree solely inside controller.