Two callbacks for page change and page changing.
use signal_connect_after() for page changed event,
as everywhere else, this should also make it
possible to select a different page in the
event handler.
GetSelection just uses native call.
Don't use m_skipEvent flag, disconnect from events.
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@43051 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775