[autobuild] create m4/ before calling autoreconf

From: Stefan Bühler <stbuehler@web.de>

git-svn-id: svn://svn.lighttpd.net/lighttpd/branches/lighttpd-1.4.x@2917 152afb58-edef-0310-8abb-c4023f1b3aa9

autogen.sh

@@ -3,5 +3,12 @@
 
 set -e
 
+if [ ! -f configure.ac -o ! -f COPYING ]; then
+	echo "Doesn't look like you're in the source directory" >&2
+	exit 1
+fi
+
+# old autoreconf/aclocal versions fail hard if m4 doesn't exist
+mkdir -p m4
 autoreconf --force --install
 echo "Now type './configure ...' and 'make' to compile."