Introducing Backbone.Self for self referencing resolves #48
Introduce explicit cleanup if you set any child graph to falsy value directly
Allow for relatedModel to be a function - discussion #23
Pass relation as second argument to relatedModel function.

For one example of where this is useful, please see:

https://gist.github.com/monokrome/5954751

This happens in any case where a function is abstracted out and the relation data can not be assumed, so I would think that it would be a fairly common issue.
Verify that the expected relation is passed.
Modified test for #50 to represent a usage example.
Removed a sneaky tab.
Extracted key string into a variable.
Merge pull request #50 from monokrome/master

Provide the relation itself to relatedModel function handlers.
Update test case and change order of parameters - Discussion #23
Upgrade underscore.js to v1.5.1
Update for upcoming release features
Update for v0.5.1 release
Update for v0.5.1 release