The need to re-create the toc after the tree has been created has been removed.  There is now a toc singleton that is populated with the `Page` models whenever a new page is created.  I would prefer to have `Content` simply listen directly to `Page` events, although that was causing some issues, apparently due to backbone-associations overriding trigger.

The other option is to use app-wide events, which I may look into implementing soon.