Bug 314761 components.e4xmi should be processed in bundle-dependency order
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/workbench/ui/internal/ModelExtensionProcessor.java
String attrURI = ce.getAttribute("uri"); 
				if (attrURI == null) {
					log("Unable to find location for the model extension \"{0}\"", 
							contributor.getName());
					continue;
				}
				URI uri;
				String bundleName = contributor.getName();
				String path = bundleName + '/' + attrURI;
				try {
					uri = URI.createPlatformPluginURI(path, false);
				} catch (RuntimeException e) {
					log("Model extension has invalid location", e); 
					continue;
				}
				ResourceSet resourceSet = ((EObject) e4Window).eResource().getResourceSet();
				Resource resource;
				try {
					resource = resourceSet.getResource(uri, true);
				} catch (RuntimeException e) {
					log("Unable to read model extension", e); 
					continue;
				}
				EList<?> contents = resource.getContents();
				if (contents.isEmpty())
					continue;
				Object extensionRoot = contents.get(0);
				if (!(extensionRoot instanceof MModelComponents)) {
					log("Unable to create model extension \"{0}\"", 
							contributor.getName());