Bug 306251 MContext's properties needs to actually be populated into the context
Need to fix CPR and then add the code in PRE.
bundles/org.eclipse.e4.ui.workbench.swt/src/org/eclipse/e4/ui/workbench/swt/internal/PartRenderingEngine.java
Assert.isNotNull(renderer);
		MUIElement parent = element.getParent();
		AbstractPartRenderer parentRenderer = parent != null ? getRendererFor(parent)
				: null;
		if (parentRenderer != null) {
			parentRenderer.hideChild(element.getParent(), element);
		}
		renderer.disposeWidget(element);
		
		if (element instanceof MContribution) {
			((MContribution) element).setObject(null);
		}
		
		if (element instanceof MContext) {
			MContext ctxt = (MContext) element;
			IEclipseContext lclContext = ctxt.getContext();
			IEclipseContext parentContext = (IEclipseContext) lclContext
					.get(IContextConstants.PARENT);
			ctxt.setContext(null);
			if (lclContext instanceof IDisposable) {
				((IDisposable) lclContext).dispose();
			}
		}
	}
	protected Object createWidget(MUIElement element, Object parent) {
		AbstractPartRenderer renderer = getRenderer(element, parent);
		if (renderer != null) {
			Object newWidget = renderer.createWidget(element, parent);
			if (newWidget != null) {
				renderer.bindWidget(element, newWidget);