If possible, create only a single shm segment and use multiple parts of it

If possible, create only a single shm segment and use multiple parts of it

Mon Jun 26 18:53:31 2000  Owen Taylor  <otaylor@redhat.com>

	* gdk/gdkrgb.c: If possible, create only a single shm segment and
	use multiple parts of it instead of creating a bunch of separate
	segments, since the maximum number of segments per system is not
	large. (This might be worth backporting to GTK+-1.2.x if we make a
	new release )

	* gdk/gdkrgb.c: Localize a bunch of variables into the GdkRgbInfo
	structure in preparation for per-colormap GdkRGB.

	* gdk/x11/gdkimage-x11.c (gdk_image_new): Don't set gdk_use_xshm
	to False when we get EINVAL from shmget so that the caller of
	gdk_image_new can retry with a smaller segment size.