[libxml2] Add configure maintainer mode

[Daniel Veillard <veillard src gnome org>]

commit b5ca26077195148ecfe83b1e4923e7bd7ce2308d
Author: orzen <hansson mattias gmail com>
Date:   Tue Feb 9 17:23:48 2016 +0100

    Add configure maintainer mode
    
    For https://bugzilla.gnome.org/show_bug.cgi?id=761784
    
    I wasn't able to build libxml2 because aclocal-1.13 was missing from
    my machine. With AM_MAINTAINER_MODE, I'm able to configure libxml2 with
    '--disable-maintainer-mode' which will disable checks for aclocal.

 configure.ac |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 0260281..55a5a6f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3,6 +3,7 @@ AC_PREREQ([2.63])
 AC_INIT
 AC_CONFIG_SRCDIR([entities.c])
 AC_CONFIG_HEADERS([config.h])
+AM_MAINTAINER_MODE([enable])
 AC_CONFIG_MACRO_DIR([m4])
 AC_CANONICAL_HOST