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.

lib/libcurses/shlib_version

@@ -1,8 +1,2 @@
-#	$NetBSD: shlib_version,v 1.40 2009/01/11 03:07:47 christos Exp $
-#	Remember to update distrib/sets/lists/base/shl.* when changing
-#	Remember to run `make fileio.h` when changing
-#	Remember to increment the major numbers of both libform and libmenu
-#	when the libcurses major number increments.
-#
-major=7
+major=0
 minor=0