added input_output_iterator_archetype

[SVN r21578]

concept_check_test.cpp

@@ -137,6 +137,11 @@ main()
     typedef output_iterator_archetype<int> Iter;
     function_requires< OutputIteratorConcept<Iter, int> >();
   }
+  {
+    typedef input_output_iterator_archetype<int> Iter;
+    function_requires< InputIteratorConcept<Iter> >();
+    function_requires< OutputIteratorConcept<Iter, int> >();
+  }
   {
     typedef forward_iterator_archetype<null_archetype<> > Iter;
     function_requires< ForwardIteratorConcept<Iter> >();