Bug 218884 [DataBinding] Add API: WorkbenchObservables
... for things like listening to ISelectionService
bundles/org.eclipse.core.databinding.observable/src/org/eclipse/core/databinding/observable/Observables.java
* @return an observable list backed by the given unchanging list
	 * @since 1.1
	 */
	public static IObservableList staticObservableList(Realm realm, List list,
			Object elementType) {
		return new ObservableList(realm, list, elementType) {
			public synchronized void addChangeListener(IChangeListener listener) {
			}
			public synchronized void addStaleListener(IStaleListener listener) {
			}
			public synchronized void addListChangeListener(IListChangeListener listener) {
			}
		};
	}
	/**
	 * Returns an observable value of type <code>Boolean.TYPE</code> which
	 * tracks whether the given observable is stale.
	 * 
	 * @param observable
	 *            the observable to track
	 * @return an observable value which tracks whether the given observable is
	 *         stale
	 * 
	 * @since 1.1
	 */
	public static IObservableValue observeStale(IObservable observable) {
		return new StalenessObservableValue(observable);
	}
	/**
	 * Returns an observable value that tracks changes to the value of an