We're going to add back the original struct definition removed by
a6e4de28, because using the typedef breaks all sorts of things like
gtkmm and WebKit, and having separate struct definitions allows us to
change the types in GdkBorder from gint16s to gints without breaking
ABI.
* Cover letter
Having a single header file for all autocleanups definitions was a
reasonable stop-gap measure, but now GTK+ is starting to use G_DECLARE_*
macros. This means that every class using a G_DECLARE_* macro will need
to include "gtk.h" to avoid compiler warnings, which is not acceptable.
By moving the G_DEFINE_AUTO* use to the header that defines the type we
allow using the G_DECLARE_* macros without sacrificing the ability to
include only the needed files when deriving from a class.
* Commit
This commit changes all includes relative to GtkWindow to define their
own autocleanup macros.