Ensure decoded views are correct by verifying they retain their connections and
respond as before archiving.
A decoded table no longer raises, and decoded button bars, tab views, text
fields and outlines retain their observers, selection, delegates and data source
methods.
* CPButtonBar: Observe the hidden state of decoded buttons.
* CPOutlineView: Decode the data source and delegate through their setters.
* CPTableView: Set the data source and delegate after _init during decoding.
* CPTabView: Select the archived tab view item during decoding, before the
delegate is set.
* CPTextField: Archive the delegate.
* CPViewDecodedBehaviorTest: Verifies connections, the view hierarchy, and the
behaviour of objects each class creates or observes after decoding.
