Widget-Parent is an extension designed to be used with Base.build, to create

widget classes which can manage nested child widgets.

For example, it could be used to create Menu widgets, which contain MenuItem

widgets, or Tree widgets, which contain TreeNode widgets.

3.3.0

* Changed instanceof to Y.instanceOf, to prevent leaks in IE7

* Renamed "type" in child configuration, to "childType", so that

children can have a "type" attribute for it's own context

(A FormElement widget for examplei, with a "type").

"type" is still supported but deprecated for backward compatibility,

so it's only used to define a child widget type if "childType" is not

provided.

* Fixed remove(), to actually remove child from DOM also.

3.2.0

* No changes

3.1.1

* No changes

3.1.0

* "childAdded" event renamed to "addChild"

* "childRemoved" event renamed to "removeChild"

* Now augmented with Y.ArrayList

* "selection" attribute now returns an Y.ArrayList or Widget

* Removed "children" attribute since that functionality is provided

by Y.ArrayList

- Can retrieve # of child via the size() method

- Can iterate children via this.each()

- Can retrieve a individual child via the item() method

* add method will always return a Y.ArrayList instance for easy chaining

* removeAll method will always return a Y.ArrayList instance for easy chaining

* added selectAll() and deselectAll() methods

* widget UI will render children added/inserted children after widget is rendered

* widget UI will update when a child is removed