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/DataBindingContext.java
*            or changed after it is passed to #bind.
	 * @return The Binding that manages this data flow
	 */
	public Binding bindList(IObservableList targetObservableList,
			IObservableList modelObservableList, BindSpec bindSpec) {
		if (bindSpec == null) {
			bindSpec = new DefaultBindSpec();
		}
		fillBindSpecDefaults(this, bindSpec, targetObservableList.getElementType(), modelObservableList.getElementType());
		Binding result = new ListBinding(this, targetObservableList,
				modelObservableList, bindSpec);
        bindings.add(result);
		return result;
	}
	/**
	 * Tries to create a converter that can convert from values of type
	 * fromType. Returns <code>null</code> if no converter could be created.
	 * Either toType or modelDescription can be <code>null</code>, but not
	 * both. The implementation of this method will iterate over the registered
	 * bind support factories in reverse order, passing the given arguments to
	 * {@link BindSupportFactory#createConverter(Object, Object)}. The first
	 * non-null converter will be returned.
	 * 
	 * @param fromType
	 * @param toType
	 * @return an IConverter, or <code>null</code> if unsuccessful
	 */
	public IConverter createConverter(Object fromType, Object toType) {
		for (int i = bindSupportFactories.size() - 1; i >= 0; i--) {
			BindSupportFactory bindSupportFactory = (BindSupportFactory) bindSupportFactories