The current design of IPython uses Components that 1) know how to configure themselves and 2) automatically track their instances and have an API for retrieving those instances. I think we need to rethink the auto-tracking and the querying API for Components as it feels a bit too magic. I think we want something that is a bit more pedestrian and explicit. Another problem is that Component.get_instances will return all instances and if you get multiple back, there really isn't a godo way of deciding which to use.
This was fixed this summer with the move from Component -> Configurable.
deleting library items removes them from the queue as well. closes #117