set major version of shlibs to 0

WARNING: this will break existing dynamically linked binaries if they
exist. If you have any:
	. re-build world statically first if necessary
	. remove libraries from /lib and /usr/lib
	. then build world

This change:
	. avoids possible future dismay when interfacing other
	  systems' binaries; done until they are abi-compatible

Thanks to Antoine Leca for pointing this out.

external/bsd/file/lib/shlib_version

@@ -1,4 +1,2 @@
-#	$NetBSD: shlib_version,v 1.1 2009/05/08 17:28:02 christos Exp $
-#
-major=3
+major=0
 minor=0

external/bsd/libarchive/lib/libarchive/shlib_version

@@ -1,6 +1,2 @@
-#	$NetBSD: shlib_version,v 1.1 2010/02/20 02:55:53 joerg Exp $
-#	Remember to update distrib/sets/lists/base/shl.* when changing
-#
-
-major=3
-minor=1
+major=0
+minor=0

external/public-domain/xz/lib/shlib_version

@@ -1,4 +1,2 @@
-#	$NetBSD: shlib_version,v 1.1 2010/11/02 16:34:36 joerg Exp $
-#
-major=1
+major=0
 minor=0