[libcroco] configure: generate xz on distcheck

[Ignacio Casal Quinteiro <icq src gnome org>]

commit 41a7708862c21ee46a38236c8c1e571179746349
Author: Ignacio Casal Quinteiro <icq gnome org>
Date:   Sat Oct 31 09:54:10 2015 +0100

    configure: generate xz on distcheck

 configure.ac |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index c42cf46..150a910 100644
--- a/configure.ac
+++ b/configure.ac
@@ -4,7 +4,8 @@ AC_INIT([libcroco],[0.6.9],[http://bugzilla.gnome.org/enter_bug.cgi?product=libc
 AC_CONFIG_SRCDIR([src/cr-input.c])
 AC_CANONICAL_HOST
 
-AM_INIT_AUTOMAKE([1.9 no-dist-gzip dist-bzip2])
+# gnu strictness to generate the INSTALL file
+AM_INIT_AUTOMAKE([1.13 tar-ustar dist-xz no-dist-gzip -Wno-portability gnu])
 AC_CONFIG_HEADERS([config.h])
 
 if test -z "$enable_maintainer_mode"; then