Too many items in tab index when navigation pane is expanded. #294
Description
When navigation pane is expanded, once you tab through all of the items in the menu the tab index moves to the focusable controls on the page "behind" the navpane. Once we have no-hide-descendants working, we can use that. In the meantime, a potential workaround is to force the focus to loop back to the start of the navigation pane.
