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/BindSpec.java
*            converters.
	 * @return this BindSpec, to enable chaining of method calls
	 */
	public BindSpec setModelToTargetConverter(IConverter converter) {
		modelToTargetConverter = converter;
		return this;
	}
	/**
	 * @param modelUpdatePolicy
	 *            The modelUpdatePolicy to set.
	 * @return this BindSpec, to enable chaining of method calls
	 */
	public BindSpec setModelUpdatePolicy(Integer modelUpdatePolicy) {
		this.modelUpdatePolicy = modelUpdatePolicy;
		return this;
	}
	/**
	 * Sets the validator for validating partial target values.
	 * 
	 * @param validator
	 *            the validator, or <code>null</code> for no validation.
	 * @return this BindSpec, to enable chaining of method calls
	 */
	public BindSpec setPartialTargetValidator(IValidator validator) {
		partialTargetValidator = validator;
		return this;
	}
	/**
	 * Sets the target to model converter.
	 *