derickbailey/backbone.marionette — pull request #194 by marten (2012-07-21 12:31:47+00:00)
Title: Throw an error when itemViewContainer can not be found

I'm still learning Backbone and Marionette, and had wrongfully assumed that the itemViewContainer selector should be scoped manually to the container view. So I had `itemViewContainer: ".discussions table"`. This confusingly did not render any items.

The reason of course is that that selector is automatically scoped to the container element, and thus it returned an empty set of elements. And then `$container.append(iv.el)` does nothing. This pull request throws an error when no elements matched the selector specified by itemViewContainer, so that typos, template changes or misconceptions don't silently fail to render any of the items in the collection.