Avoid memory leaks during refresh - DO NOT MERGE

This is intended to get some discussion around a solution for memory leaks around elements that are removed during a refresh (http://bugs.jqueryui.com/ticket/10056).

Unfortunately, I don't think there's a general solution we can apply. Every widget that handles a refresh will need to manually track the removed elements and pass them to `._off()`.
I'm generating new `jQuery` instances from arrays to avoid the `.prevObject` history. This history actually gets really deep really quickly. Removing the history is required to prevent the memory leak. We could just `delete this.bindings.prevObject`, but that feels a little dirty. @dmethvin thoughts?