Shorten copyright notice.

Shorten copyright notice.

The GPLv2 line does not add any additional information, so drop
it. This leaves a single line of legalese text for most files, which
is about the amount of screen real estate it deserves.

This patch was created with the following script (plus some manual
fixups):

	awk '{
		if (NR <= 5) {
			gs = gensub(/.*Copyright.* ([0-9]+).*Andre Noll.*/, "\\1", "g")
			if (gs != $0)
				year = gs
			next
		}
		if (NR == 6 && year != "")
			printf("/* Copyright (C) %s Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */\n", year)
		print
	}'