Adds isNodeAttached helper method.

PR 1 for `onAttach`

This adds a helper method `isNodeAttached`. It lets you know if an element is a child of the document or not. I also updated `triggerDOMRefresh` to take advantage of the new helper.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/f/f8/Dashboard_dec_06_toronto.jpg/330px-Dashboard_dec_06_toronto.jpg)