Initialize wxAuiNotebookXmlHandler::m_isInside in ctor.

Closes #15694.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75269 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
More version change related changes to the generated files.

Somehow not all files seem to have been regenerated after version.bkl change.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75270 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Add XRC handler for wxAuiToolBar.

Also add the demonstration of AUI handlers (this one and the existing one for
wxAuiNotebook) to the xrc sample.

See #15686.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75271 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775