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
return false;
	}
	private void constructDeltas(Collection<ModelDelta> deltas, List<Object> references,
			EObject object, Element element) {
		String elementName = element.getNodeName();
		if (elementName.equals(CONTEXT_PROPERTIES_ATTNAME)) {
			constructEntryDelta(deltas, UiPackageImpl.eINSTANCE.getContext_Properties(), object,
					element);
		} else if (elementName.equals(CONTRIBUTION_PERSISTEDSTATE_ATTNAME)) {
			constructEntryDelta(deltas, ApplicationPackageImpl.eINSTANCE
					.getContribution_PersistedState(), object, element);
		} else {
			constructObjectDeltas(deltas, references, object, element);
		}
	}
	private void constructEntryDelta(Collection<ModelDelta> deltas, EStructuralFeature feature,
			EObject object, Element element) {
		if (element.getAttribute(UNSET_ATTNAME).equals(UNSET_ATTVALUE_TRUE)) {
			EMFDeltaEntrySet delta = new EMFDeltaEntrySet(object, feature, element
					.getAttribute(ENTRY_ATTVALUE_KEY), null);
			deltas.add(delta);
		} else {
			EMFDeltaEntrySet delta = new EMFDeltaEntrySet(object, feature, element
					.getAttribute(ENTRY_ATTVALUE_KEY), element.getAttribute(ENTRY_ATTVALUE_VALUE));
			deltas.add(delta);
		}
	}
	private void constructObjectDeltas(Collection<ModelDelta> deltas, List<Object> references,
			EObject object, Element element) {
		NodeList nodeList = (NodeList) element;