Bug 118429 [DataBinding] Validation should use IStatus, not just Strings
In order to use data binding in Workbench or IDE dialogs and preference pages, we need validation in terms of IStatus objects. Using strings is too simplistic. For example, look at the wizard for creating a new class. You will get a warning if the class name does not start with an uppercase letter, or if you don't provide a package name, but you will still be able to click "Finish" to proceed anyway. (Note that IStatus is currently not on the classpath, we need to re-introduce the dependency on org.eclipse.equinox.common, which contains IStatus etc.)
bundles/org.eclipse.core.databinding/src/org/eclipse/core/databinding/BindSpec.java
private Integer targetUpdatePolicy;
	private boolean updateModel = true;
	private boolean updateTarget = true;
	private static final IValidator[] EMPTY_VALIDATORS = new IValidator[0];
	private static final IConverter[] EMPTY_CONVERTERS = new IConverter[0];
	/**
	 * Default constructor that initializes all objects to their defaults.
	 */
	public BindSpec() {
	}
	
	/**
	 * Creates a bind spec with the given converters, validators, and update
	 * policies.
	 * 
	 * @param modelToTargetConverter
	 * @param targetToModelConverter
	 * @param targetValidator
	 * @param domainValidator
	 * @param modelUpdatePolicy
	 * @param validatePolicy
	 * @param targetUpdatePolicy 
	 * 
	 */
	protected BindSpec(IConverter[] modelToTargetConverter,
			IConverter[] targetToModelConverter, IValidator[] targetValidator,
			IDomainValidator domainValidator, Integer modelUpdatePolicy,
			Integer validatePolicy, Integer targetUpdatePolicy) {
		
		this.modelToTargetConverters = modelToTargetConverter;