idAttribute causing bug in Supermodel

[wookiehangover]

We've recently uncovered a bug in Supermodel pathable/supermodel#57 that prevents Items from being stored in their singleton backing collection.

This happened in 6b1e9e when we added the idAttribute property to the item model. There appears to be a work-around that I'm looking into presently, but I wanted to give folks a heads up before I opened a PR.

cc/ @justinabrahms @joestump

[wookiehangover]

finally figured it out – full solution here: http://jsbin.com/golucuduwa/2/edit?js,console

tl;dr – you've gotta make sure to call super if you override initialize in a supermodel

[nonsensery]

FWIW, there's a typo in that JSBin... it says:

var Collection2 = Backbone.Collection.extend({
  model: function(attrs, options) {
    return Model.create(attrs, options);
  }
});

But it should be calling create() on Model2, like: http://jsbin.com/sotilibeja/1/edit?js,console