AUI-849 - Treeview generated from markup does not expand or collapse

Hi Jon,

Attached is an update for https://issues.liferay.com/browse/AUI-849.

I was able to do do the HTML parsing recursively as you suggested, but had to break it out into a separate function that I could invoke recursively and from the HTML_PARSER.

I also wrote a unit test for this issue.

Please let me know if there are any issues.

Thanks!