Bug 182780 [DataBinding] Default a converter for IStatus to String
The converter used to display an IStatus uses toString(). This outputs a fairly ugly status message. We should create a default converter and use this in UpdateValueStrategy to return just the message of the status.
bundles/org.eclipse.core.databinding/src/org/eclipse/core/databinding/AggregateValidationStatus.java
* the given bindings are the an OK status. Returns a single status if there
	 * is only one non-OK status.
	 * 
	 * @param bindings
	 *            a collection of bindings
	 * @return a merged status
	 */
	public static IStatus getStatusMerged(Collection bindings) {
		List statuses = new ArrayList();
		for (Iterator it = bindings.iterator(); it.hasNext();) {
			Binding binding = (Binding) it.next();
			IStatus status = (IStatus) binding
					.getValidationStatus().getValue();
			if (!status.isOK()) {
				statuses.add(status);
			}
		}
		if (statuses.size() == 1) {
			return (IStatus) statuses.get(0);
		}
		if (!statuses.isEmpty()) {
			MultiStatus result = new MultiStatus(
					Policy.JFACE_DATABINDING,
					0,
					BindingMessages
							.getString(BindingMessages.MULTIPLE_PROBLEMS),
					null);
			for (Iterator it = statuses.iterator(); it.hasNext();) {
				IStatus status = (IStatus) it.next();
				result.merge(status);