Bug 198880 [DataBinding] ObservablesManager does not dispose model
bundles/org.eclipse.core.databinding/src/org/eclipse/core/databinding/ObservablesManager.java
private Set managedObservables = new HashSet();
	private Set excludedObservables = new HashSet();
	private Map contexts = new HashMap();
	/**
	 * Create a new observables manager.
	 */
	public ObservablesManager() {
	}
	/**
	 * Adds the given observable to this manager.
	 * 
	 * @param observable
	 *            the observable
	 */
	public void addObservable(IObservable observable) {
		managedObservables.add(observable);
	}
	/**