configure: fix automake 1.13 compatibility

Tested with:

buildconf: autoconf version 2.69
buildconf: autom4te version 2.69
buildconf: autoheader version 2.69
buildconf: automake version 1.13.1
buildconf: aclocal version 1.13.1
buildconf: libtool version 2.4
buildconf: GNU m4 version 1.4.16

configure.ac

@@ -5,6 +5,7 @@ AC_INIT([c-ares], [-],
   [c-ares mailing list: http://cool.haxx.se/mailman/listinfo/c-ares])
 
 XC_OVR_ZZ50
+XC_OVR_ZZ60
 CARES_OVERRIDE_AUTOCONF
 
 AC_CONFIG_SRCDIR([ares_ipv6.h])

m4/cares-override.m4

@@ -2,7 +2,7 @@
 #***************************************************************************
 
 # File version for 'aclocal' use. Keep it a single number.
-# serial 6
+# serial 7
 
 dnl CARES_OVERRIDE_AUTOCONF
 dnl -------------------------------------------------
@@ -89,12 +89,3 @@ m4_defun([_LT_AC_LIBTOOL_SYS_PATH_SEPARATOR],
 [CARES_CHECK_PATH_SEPARATOR
 m4_define([$0],[])])
 
-dnl Provide Autoconf's AC_CONFIG_MACRO_DIR (DIR)
-dnl -------------------------------------------------
-dnl Allow usage of mentioned macro in configure.ac
-dnl even with ancient Autoconf versions, such as 2.57,
-dnl that do not provide a definition for this macro.
-
-m4_ifndef([AC_CONFIG_MACRO_DIR],
-[AC_DEFUN([AC_CONFIG_MACRO_DIR],[:])])
-

m4/zz60-xc-ovr.m4

@@ -0,0 +1,64 @@
+#---------------------------------------------------------------------------
+#
+# zz60-xc-ovr.m4
+#
+# Copyright (c) 2013 Daniel Stenberg <daniel@haxx.se>
+#
+# Permission to use, copy, modify, and distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+#
+#---------------------------------------------------------------------------
+
+# serial 1
+
+
+dnl The funny name of this file is intentional in order to make it
+dnl sort alphabetically after any libtool, autoconf or automake
+dnl provided .m4 macro file that might get copied into this same
+dnl subdirectory. This allows that macro (re)definitions from this
+dnl file may override those provided in other files.
+
+
+dnl Override an autoconf provided macro
+dnl -------------------------------------------------
+dnl This macro overrides the one provided by autoconf
+dnl 2.58 or newer, and provides macro definition for
+dnl autoconf 2.57 or older which lack it. This allows
+dnl using libtool 2.2 or newer, which requires that
+dnl this macro is used in configure.ac, with autoconf
+dnl 2.57 or older.
+
+m4_ifdef([AC_CONFIG_MACRO_DIR],
+[dnl
+m4_undefine([AC_CONFIG_MACRO_DIR])dnl
+])
+m4_define([AC_CONFIG_MACRO_DIR],[])
+
+
+dnl XC_OVR_ZZ60
+dnl -------------------------------------------------
+dnl Placing a call to this macro in configure.ac will
+dnl make macros in this file visible to other macros
+dnl used for same configure script, overriding those
+dnl provided elsewhere.
+
+AC_DEFUN([XC_OVR_ZZ60],
+[dnl
+AC_BEFORE([$0],[LT_INIT])dnl
+AC_BEFORE([$0],[AM_INIT_AUTOMAKE])dnl
+AC_BEFORE([$0],[AC_LIBTOOL_WIN32_DLL])dnl
+AC_BEFORE([$0],[AC_PROG_LIBTOOL])dnl
+dnl
+AC_BEFORE([$0],[AC_CONFIG_MACRO_DIR])dnl
+AC_BEFORE([$0],[AC_CONFIG_MACRO_DIRS])dnl
+])
+