Attaching idAttribute, defaults, urlRoot, collection if passed

I went to do this today:
```js
new UserView({model: new Backbone.Model({}, {urlRoot:'/user'}));
```
and was forgot that it wasn't possible to do. 

So I took a look and thought it would be nice if the `Model` mimicked the `View` in taking anything out of the options hash which would make sense to attach directly (`idAttribute`, `defaults`, `urlRoot`, and `collection`) so it's easier to create one-off models without using an unnecessary `Model.extend`.