Copy our gdkprivate.h and gdkx.h to a gdk subdirectory, so that

Copy our gdkprivate.h and gdkx.h to a gdk subdirectory, so that

	* gdk/win32/makefile.{cygwin,msc}: Copy our gdkprivate.h and
 	gdkx.h to a gdk subdirectory, so that applications can include
 	these with <gdk/*.h> without trouble.

	* gdk/win32/gdkimage.c (gdk_image_new_with_depth): Code simplified.
	(gdk_image_destroy): Plugged resource leak, some GdkImages didn't
	have their bitmap destroyed.

	* gdk/win32/gdk.def: Add gdk_root_parent.