include config.h

[[Imported from SVN: r647]]

istl/tutorial/example.cc

 // -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 // vi: set et ts=4 sw=2 sts=2:
 // start with including some headers
+#include "config.h"
+
 #include <iostream>               // for input/output to shell
 #include <fstream>                // for input/output to files
 #include <vector>                 // STL vector class