Support MSVC 2010 beta 1.

src/google/protobuf/stubs/strutil.cc

@@ -36,6 +36,7 @@
 #include <limits>
 #include <limits.h>
 #include <stdio.h>
+#include <iterator>
 
 #ifdef _WIN32
 // MSVC has only _snprintf, not snprintf.

vsprojects/config.h

@@ -5,7 +5,11 @@
 #define HASH_MAP_H <hash_map>
 
 /* the namespace of hash_map/hash_set */
-#if _MSC_VER < 1310
+// Apparently Microsoft decided to move hash_map *back* to the std namespace
+// in MSVC 2010:
+//   http://blogs.msdn.com/vcblog/archive/2009/05/25/stl-breaking-changes-in-visual-studio-2010-beta-1.aspx
+// TODO(kenton):  Use unordered_map instead, which is available in MSVC 2010.
+#if _MSC_VER < 1310 || _MSC_VER >= 1500
 #define HASH_NAMESPACE std
 #else
 #define HASH_NAMESPACE stdext