AGW on Phoenix: apply Rob's patch: when using DetachPane on panes in an automatic notebook. If you remove all the panes from the notebook and then call UpdateNotebook, the notebook gets removed, but the panes hadn't been reparented to the frame so they get destroyed. Back-ported from Classic.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxPython/Phoenix/trunk@75577 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775