checks for autoconf version

autogen.sh

@@ -1,10 +1,20 @@
 #!/bin/sh
+required_version=52
+echo -n "Checking for autoconf version >= "${required_version}"......"
+ac_version=`autoconf --version|head -n 1|cut -d . -f 2`
+if [ ${ac_version} -lt ${required_version} ]; then
+	echo "No."
+	echo "You need to install autoconf version >= "${required_version}
+	exit 1
+fi
+echo "Ok."
+
 libtoolize --copy --force --automake || exit 1
 rm -f config.cache
 aclocal
 autoheader
 automake -a
 autoconf
-
+echo "Done."