And, since we've decided to keep the structs private, there is no point in having the standard GObject clas macros anymore either.
And nuke GdkDeviceManagerPrivate at the same time. Again a commit that only deals with the X11 backend, other backends will need to catch up.
This function makes a better replacement for gdk_display_get_core_pointer(), wherever it might yet be needed, for XI2 resorts to XIGetClientPointer(), for the others return the only core pointer. https://bugzilla.gnome.org/show_bug.cgi?id=621685
