Bug 205248 [Databinding] Observables on Text with FOCUS_OUT event incorrectly notify with no change
If you get an observable on a Text for the FOCUS_OUT event, the model is updated every time, even if there is no change in the value. The observable should not trigger a model change if the Text value is the same as the model value.
bundles/org.eclipse.core.databinding/src/org/eclipse/core/databinding/observable/value/AbstractVetoableValue.java
* 
	 * @param value
	 */
	protected abstract void doSetApprovedValue(Object value);
	public synchronized void addValueChangingListener(
			IValueChangingListener listener) {
		addListener(ValueChangingEvent.TYPE, listener);
	}
	public synchronized void removeValueChangingListener(
			IValueChangingListener listener) {
		removeListener(ValueChangingEvent.TYPE, listener);
	}
	/**
	 * Notifies listeners about a pending change, and returns true if no
	 * listener vetoed the change.
	 * 
	 * @param diff
	 * @return false if the change was vetoed, true otherwise
	 */
	protected boolean fireValueChanging(ValueDiff diff) {
		checkRealm();
		ValueChangingEvent event = new ValueChangingEvent(this, diff);
		fireEvent(event);
		return !event.veto;
	}
	public synchronized void dispose() {
		super.dispose();
	}
}