[librsvgmm] Explicitly require libtool >= 2.2.0

[Daniel Elstner <daniel src gnome org>]

commit 94f2e2c3c3b67be3cb073395153135b42a66c369
Author: Daniel Elstner <daniel kitta gmail com>
Date:   Sun Jun 21 04:31:01 2009 +0200

    Explicitly require libtool >= 2.2.0
    
    * configure.ac: Use LT_PREREQ to specify the minimum libtool version.

 configure.ac |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index c95358c..b9c6ecd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -33,6 +33,7 @@ AC_PROG_CXX
 # http://www.gnu.org/software/libtool/manual/html_node/Updating-version-info.html
 AC_SUBST([LIBRSVGMM_SO_VERSION], [0:0:0])
 
+LT_PREREQ([2.2.0])
 LT_INIT([disable-static win32-dll])
 
 # Doxygen needs the path to the installed Perl