Bug 290964 Factor out model loading from Workbench so that it is plugable
We want to support different workbench restoreing possibilities and for this we need to delegate the loading to an external instance
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/workbench/ui/internal/Workbench.java
public static final String LOCAL_ACTIVE_SHELL = "localActiveShell"; 
	public static final String ID = "org.eclipse.e4.workbench.fakedWBWindow"; 
	private MApplication workbench;
	private static final boolean saveAndRestore = true;
	private File workbenchData;
	private IWorkbenchWindowHandler windowHandler;
	
	private ResourceSetImpl resourceSet;
	public IEclipseContext getContext() {
		return workbenchContext;
	}
	
	private IPresentationEngine renderer;
	private int rv;
	private ExceptionHandler exceptionHandler;
	private IEclipseContext workbenchContext;
	private ReflectionContributionFactory contributionFactory;
	private String renderingEngineURI;
	public Workbench(Location instanceLocation, IExtensionRegistry registry,
			PackageAdmin packageAdmin, IEclipseContext applicationContext,
			IWorkbenchWindowHandler windowHandler, String renderingEngineURI) {
		
		this.windowHandler = windowHandler;
		this.renderingEngineURI = renderingEngineURI;
		exceptionHandler = new ExceptionHandler();