Extract private methods when generating documentation too.

The only private methods appearing in interface/wx/*.h files are meant to be
documented, so do extract them. This should fix wxThread::OnExit() not
appearing in the generated documentation, for example.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75858 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Use "state-flags-changed" signal with GTK3, deprecated "state-changed" is ignored.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75861 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
get non-default wxTextCtrl cursors working with GTK3

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75862 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
emit signal by id instead of name

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75863 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
add missing GTK3 implementations of GTKGetWindow()

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75864 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775