PDI-10581 - calling firePropertyChange with the correct previously selected item.  passing null cause an infinite recursion.
Merge pull request #171 from kurtwalker/PDI-10581

PDI-10581
PDI-10581 - adding a binding to the menulist to indicated which attribute should be used as the element value
Merge pull request #172 from kurtwalker/PDI-10581

PDI-10581