Fix compile-errors on older versions of GCC (missing definitions - thanks to lynx3d for the heads up)

(users are adviced to upgrade to a MORE RECENT version of GCC that supports the standardized tr1::unordered_map functionality though)

--HG--
branch : trunk

src/server/shared/Dynamic/UnorderedMap.h

@@ -62,7 +62,13 @@ namespace __gnu_cxx
     {
         size_t operator()(T * const &__x) const { return (size_t)__x; }
     };
-
+    template<> struct hash<std::string>
+    {
+        size_t operator()(const std::string &__x) const
+        {
+            return hash<const char *>()(__x.c_str());
+        }
+    };
 };
 
 #else