Bug 317954 Version deltas file so that incompatible changes will be ignored
The deltas file needs to be versioned so that incompatible changes will be discarded allowing the workbench to be constructed as if there were no deltas in existence.
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/internal/workbench/XMLModelReconciler.java
if (!collectedFeature.isTransient() && shouldPersist(featureName)) {
				Element referenceAttributeElement = createAttributeElement(document, eObject,
						collectedFeature, featureName);
				referenceElement.appendChild(referenceAttributeElement);
			}
		}
		return referenceElement;
	}
	private Element createUniqueReferenceElement(Document document, EObject eObject) {
		EClass cls = eObject.eClass();
		EPackage pkg = (EPackage) cls.eContainer();
		Element referenceElement = document.createElement(REFERENCE_ELEMENT_NAME);
		E4XMIResource resource = (E4XMIResource) rootObject.eResource();
		String internalId = resource.getInternalId(eObject);
		referenceElement.setAttribute(XMIID_ATTNAME, internalId);
		referenceElement.setAttribute(NAMESPACE_ATTNAME, pkg.getNsURI());
		return referenceElement;
	}
	/**
	 * Creates an element that describes the state of the feature in the specified object.
	 * 
	 * @param document
	 *            the root XML element document
	 * @param object
	 *            the object to describe
	 * @param feature
	 *            the feature of interest
	 * @param featureName
	 *            the name of the feature
	 * @return an XML element that describes the feature's value in the provided object