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
private Element createSetDeltaElement(Document document, EObject object,
			FeatureChange featureChange, String featureName, EStructuralFeature feature) {
		Element featureElement = document.createElement(featureName);
		Object value = object.eGet(feature);
		if (isSingleReference(featureName)) {
			
			
			
			
			Element referenceElement = createReferenceElement(document, (EObject) value,
					featureName);
			featureElement.appendChild(referenceElement);
		} else if (isChainedReference(featureName)) {
			
			appendReferenceElements(document, featureElement, (List<?>) value);
			
			appendOriginalReferenceElements(document, featureElement, (List<?>) featureChange
					.getValue());
		} else if (isUnorderedChainedAttribute(featureName)) {
			List<?> attributes = (List<?>) value;
			for (Object attribute : attributes) {
				Element attributeElement = document.createElement(featureName);
				attributeElement.setAttribute(featureName, String.valueOf(attribute));
				featureElement.appendChild(attributeElement);
			}
		} else if (isStringToStringMap(featureName)) {
			EMap<?, ?> map = (EMap<?, ?>) object.eGet(feature);
			for (Entry<?, ?> entry : map.entrySet()) {
				Element entryElement = document.createElement(featureName);
				entryElement.setAttribute(ENTRY_ATTVALUE_KEY, (String) entry.getKey());