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 persist(Document document, Entry<EObject, EList<FeatureChange>> entry,
			EObject object) {
		if (object instanceof Entry<?, ?>) {
			return persistEntry(document, object);
		}
		return persistObject(document, entry, object);
	}
	private Element persistObject(Document document, Entry<EObject, EList<FeatureChange>> entry,
			EObject object) {
		if (getOriginalId(object) == null) {
			return null;
		}
		Element modelChange = null;
		List<FeatureChange> featureChanges = entry.getValue();
		for (FeatureChange featureChange : featureChanges) {
			
			if (!featureChange.getFeature().isTransient()) {
				String featureName = featureChange.getFeatureName();
				
				if (shouldPersist(featureName)) {
					if (modelChange == null) {
						
						modelChange = createElement(document, object);
					}
					
					Element deltaElement = createDeltaElement(document, object, featureChange,
							featureName);
					modelChange.appendChild(deltaElement);
				}
			}