Bug 159940 [DataBinding] DataBindingContext shouldn't expose the bindings list as a mutable list
Currently in DataBindingContext getBindings() exposes the bindings observable list as a mutable observable list. I think we need to make this an unmodifiable list and also add a removeBinding(Binding binding) method to the API of DataBindingContext so that the DBC can remove itself from the binding when removed from the DBC. I'll create a patch soon.
bundles/org.eclipse.jface.databinding/src/org/eclipse/jface/databinding/DataBindingContext.java
* @param toType
	 * @param modelDescription
	 * @return an IValidator, or <code>null</code> if unsuccessful
	 */
	public IValidator createValidator(Object fromType, Object toType) {
		for (int i = bindSupportFactories.size() - 1; i >= 0; i--) {
			BindSupportFactory bindSupportFactory = (BindSupportFactory) bindSupportFactories
					.get(i);
			IValidator validator = bindSupportFactory.createValidator(fromType,
					toType);
			if (validator != null) {
				return validator;
			}
		}
		if (parent != null) {
			return parent.createValidator(fromType, toType);
		}
		return null;
	}
	/**
	 * Disposes of this data binding context and all observable objects created
	 * in this context.
	 */
	public void dispose() {
		for (Iterator it = bindings.iterator(); it.hasNext();) {
			Binding binding = (Binding) it.next();
			binding.dispose();
		}
		for (Iterator it = childContexts.iterator(); it.hasNext();) {
			DataBindingContext context = (DataBindingContext) it.next();