Tree Nodes that are disabled and in treeDefaultExpandedKeys[] are not expanded

[givethemheller]

Tree nodes that have children and are disabled will not open when their ID is int he treeDefaultExpandedKeys array. This occurs even when sub-elements are not disabled. The user can expand the node manually.

This is a use case in which the parent is not clickable (perhaps just a place holder) and the children are valid options.