This method is used to add buttons to the top bar of the default ListStyles. The
EntreeActionItem is what is used to construct these buttons.
The following example will add a button to the bar and be rendered like the screen shot.
EntreeActionItem ai = new EntreeActionItem();
ai.ActionTitle = "Pages";
ai.Position = "left";
EntreeClickActionObject co = output.CreateClickAction();
co["screen"] = "pages";
co.SlideDirection = EntreeScreenSlideDirection.Back;
ai.SetClickAction(co);
output.AddAction(ai);
