Bug 167450 [DataBinding] Get rid of bind support factory magic
I finally realized that we don't need that other magic factory. I'll move fillBindSpecDefaults() and the methods it calls (createConverter, createValidator etc) to a new class DefaultBindSpec. Clients who want default validators and converters created for them just create a DefaultBindSpec as opposed to a (rather empty) BindSpec. I will also move the early type checking into DefaultBindSpec to make it optional as well.
tests/org.eclipse.jface.tests.databinding/src/org/eclipse/jface/tests/databinding/DatabindingContextTest.java
int count;
		
		public void handleChange(IObservable source) {
			count++;
		}
	}
	private static class BindingStub extends Binding {
		DataBindingContext context;
		public BindingStub(DataBindingContext context) {
			super(context);
		}
		public IObservableValue getPartialValidationStatus() {
			return null;
		}
		public IObservableValue getValidationStatus() {
			return null;
		}
		public void updateModelFromTarget() {
		}
		public void updateTargetFromModel() {
		}
	}
}