Bug 238909 [DataBinding] Correctly set the staleness state of the validation status observable of the MultiValidator
For Bindings, the validation status observable should be stale whenever either the target or model observable is stale. For the MultiValidator, the validation status observable should be stale whenever any of its dependencies accessed from within the MultiValidator#validate() is stale.
bundles/org.eclipse.core.databinding/src/org/eclipse/core/databinding/validation/MultiValidator.java
* Returns a wrapper {@link IObservableMap} which stays in sync with the
	 * given target observable only when the validation status is valid.
	 * Statuses of {@link IStatus#OK OK}, {@link IStatus#INFO INFO} or
	 * {@link IStatus#WARNING WARNING} severity are considered valid.
	 * <p>
	 * The wrapper behaves as follows with respect to the validation status:
	 * <ul>
	 * <li>While valid, the wrapper stays in sync with its target observable.
	 * <li>While invalid, the wrapper's entries are the target observable's
	 * last valid entries. If the target changes entries, a stale event is fired
	 * signaling that a change is pending.
	 * <li>When status changes from invalid to valid, the wrapper takes the
	 * entries of the target observable, and synchronization resumes.
	 * </ul>
	 * 
	 * @param target
	 *            the target observable being wrapped. Must be in the same realm
	 *            as the MultiValidator.
	 * @return an IObservableValue which stays in sync with the given target
	 *         observable only with the validation status is valid.
	 */
	public IObservableMap observeValidatedMap(IObservableMap target) {
		checkObservable(target);
		return new ValidatedObservableMap(target, getValidationStatus());
	}
	public IObservableList getTargets() {
		return unmodifiableTargets;
	}
	public IObservableList getModels() {
		return models;