Use standard shared library versioning.

Index: gettext-tools/gnulib-lib/Makefile.in
--- gettext-tools/gnulib-lib/Makefile.in.orig
+++ gettext-tools/gnulib-lib/Makefile.in
@@ -4653,7 +4653,7 @@ libgettextlib_la_LDFLAGS = $(AM_LDFLAGS) -no-undefined
 	$(LTLIBC32CONV) $(LTLIBICONV) $(LTLIBINTL) $(LTLIBUNISTRING) \
 	$(MBRTOWC_LIB) $(POSIX_SPAWN_LIB) $(POW_LIBM) $(QCOPY_ACL_LIB) \
 	$(SERVENT_LIB) $(SETLOCALE_LIB) $(SETLOCALE_NULL_LIB) \
-	@INTL_MACOSX_LIBS@ -release @VERSION@ $(am__append_38) \
+	@INTL_MACOSX_LIBS@ $(am__append_38) \
 	$(am__append_54) $(LTLIBICONV) $(LTLIBICONV) $(am__append_175) \
 	$(am__append_176)