Bug 334644 Cannot manually un/render a window that's directly under the application
Setting the 'toBeRendered' flag for a window that's a direct child of an application does nothing. The workaround is to manually de/construct it via the IPresentationEngine.
bundles/org.eclipse.e4.ui.workbench.swt/src/org/eclipse/e4/ui/internal/workbench/swt/PartRenderingEngine.java
Activator.trace(Policy.DEBUG_RENDERER, "visible -> true", null); 
				
				Object w = createGui(changedElement);
				if (w instanceof Control && !(w instanceof Shell)) {
					fixZOrder(changedElement);
				}
			} else {
				Activator
						.trace(Policy.DEBUG_RENDERER, "visible -> false", null); 
				
				
				if (parent.getSelectedElement() == changedElement)
					parent.setSelectedElement(null);
				
				removeGui(changedElement);
			}
		}
	};
	private EventHandler visibilityHandler = new EventHandler() {
		public void handleEvent(Event event) {
			MUIElement changedElement = (MUIElement) event
					.getProperty(UIEvents.EventTags.ELEMENT);
			MElementContainer<MUIElement> parent = changedElement.getParent();
			if (parent == null)
				return;
			AbstractPartRenderer renderer = (AbstractPartRenderer) parent
					.getRenderer();
			if (renderer == null)
				return;