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 AdvancedPackageImpl.eINSTANCE.getPerspective_Windows();
		}
		Activator.log(IStatus.WARNING, "Unknown feature found, reconciliation may fail: " 
				+ object.eClass().getName() + '#' + featureName);
		for (EStructuralFeature sf : object.eClass().getEAllStructuralFeatures()) {
			if (sf.getName().equals(featureName)) {
				return sf;
			}
		}
		return null;
	}
	private Object getValue(EStructuralFeature feature, String featureValue) {
		Class<?> instanceClass = feature.getEType().getInstanceClass();
		if (instanceClass == String.class) {
			return featureValue;
		} else if (instanceClass == int.class) {
			return Integer.valueOf(featureValue);
		} else if (instanceClass == boolean.class) {
			return Boolean.valueOf(featureValue);
		} else if (feature == UiPackageImpl.eINSTANCE.getGenericTrimContainer_Side()) {
			return SideValue.getByName(featureValue);
		} else if (feature == MenuPackageImpl.eINSTANCE.getItem_Type()) {
			return ItemType.getByName(featureValue);
		}
		return null;
	}
	static Object findReference(List<Object> references, String id) {
		for (Object reference : references) {
			if (reference instanceof MApplicationElement && getLocalId(reference).equals(id)) {
				return reference;