Bug 174555 [DataBinding] Run validation on binding construction
When a binding is created the assumption is that the UI is synchronized with the model. This means that the UI should reflect the state of the model's validity as well. In order to ensure that the UI reflects the model's validity the consumer needs to force a copy to model on instantiation of every binding. We need to remove this requirement.
tests/org.eclipse.jface.tests.databinding/src/org/eclipse/jface/tests/internal/databinding/internal/ValueBindingTest_Policies.java
private WritableValue target;
	private WritableValue model;
	private DataBindingContext dbc;
	/*
	 * (non-Javadoc)
	 * 
	 * @see junit.framework.TestCase#setUp()
	 */
	protected void setUp() throws Exception {
		super.setUp();
		target = WritableValue.withValueType(String.class);
		model = WritableValue.withValueType(String.class);
		dbc = new DataBindingContext();
	}
	public void testModelUpdatePolicyNull() throws Exception {
		new ValueBinding(target, model, new BindSpec()
				.setModelUpdatePolicy(null)).init(dbc);
		target.setValue("1");
		assertEquals("should be automatic", target.getValue(), model.getValue());
	}
	public void testModelUpdatePolicyAutomatic() throws Exception {
		new ValueBinding(target, model, new BindSpec()
				.setModelUpdatePolicy(BindSpec.POLICY_AUTOMATIC)).init(dbc);
		target.setValue("1");
		assertEquals("should be automatic", target.getValue(), model.getValue());
	}
	public void testModelUpdatePolicyExplicit() throws Exception {
		ValueBinding binding = new ValueBinding(target, model, new BindSpec()