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/Binding.java
* Updates the target's state from the model's state at the next reasonable
	 * opportunity. There is no guarantee that the state will have been updated
	 * by the time this call returns.
	 */
	public abstract void updateTargetFromModel();
	
	/**
	 * Disposes of this Binding. Subclasses may extend, but must call super.dispose().
	 */
	public void dispose() {
		bindingEventListeners = null;
		context = null;
		disposed = true;
	}
	protected boolean disposed = false;
	
	/**
	 * @return true if the binding has been disposed.  false otherwise.
	 */
	public boolean isDisposed() {
		return disposed;
	}
	/**
	 * @param context
	 */
	 void setDataBindingContext(DataBindingContext context) {
		this.context = context;
	}
}