Creates a tabbed pane from the current pane.
The new tabbed pane, or NULL if the create operation failed.
The framework calls this method when it creates a tabbed pane to replace this pane. For more information, see CDockablePane::AttachToTabWnd.
Override this method in a derived class to customize how tabbed panes are created and initialized.
The tabbed pane is created according to the runtime class information stored in the m_pTabbedControlBarRTC member, which is initialized by the CDockablePane::CreateEx method.