Implement access to a global toplevel GdkWindow in a way that does not require always having an extra GtkWindow.
And don't use "RootWindow" in the name, it is not a root window in the X11 sense.
Also add wxGetPangoContext() to get access to a PangoContext.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76465 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775