2003-01-29: Jens Jakobsen <jj@openggsn.org>
	Added -L../gtp to sgsnemu and ggsn makefiles so that make will
	work without an installed libgtp.

	Added sgsnemu check to check for valid pointer when deleting tun.

	Removed enabling of ip_forward = 1 from ggsn.c and sgsnemu. From a
	security point of view it was not very good that openggsn
	automatically enabled routing.

	Added ipup, ipdown and createif to sgsnemu/cmdline.ggo. Now
	sgsnemu will set up default route and then execute ipup script
	after tun device has been set up. After tun has been deleted the
	ipdown script is executed.

	Added support for ping to sgsnemu.

	Added ipup and ipdown to ggsn/cmdline.ggo.