The primary management of content happens with views/main/main.js as a conduit. It stays alive and manages the main content area and creates/removes sub-Views as the open section changes. It knows what kind of content it is dealing with and dependent content can update (ex: sidebar) because the event routers carry around the options object that is a built-in thing that gets passed to Backbone constructors. I've just expanded its life a bit.

@cmc333333 @ascott1