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.
bundles/org.eclipse.core.databinding/src/org/eclipse/core/databinding/BindSupportFactory.java
* Creates a validator for the given from and to types and model
	 * description. Either toType or modelDescription can be null, but not both.
	 * The returned validator (if not null) should validate arbitrary values of
	 * type toType, and (in the case that toType is given) ensure that they can
	 * be converted to toType, and (in the case that modelDescription is given)
	 * ensure that they can be converted to the type expected by updatable
	 * objects created from the given model description.
	 * 
	 * @param fromType
	 *            The type to validate
	 * @param toType
	 *            The type to convert to after successful validation, or
	 *            <code>null</code> if not known
	 * @return a validator, or <code>null</code> if this factory cannot create
	 *         a validator for the given arguments.
	 */
	public IValidator createValidator(Object fromType, Object toType) {
		return null;
	}
	/**
	 * Creates a domain validator for the given model description. Either
	 * modelType or modelDescription can be null, but not both.
	 * 
	 * @param modelType
	 *            The type to validate or <code>null</code> if not known
	 * @return IDomainValidator
	 */
	public IValidator createDomainValidator(Object modelType) {
		return null;
	}