Refactoring of container usage:

* New ripple container aliases use hardened_hash
* Use std::tuple instead of boost::tuple
* Use std unordered containers instead of boost
* Fix Destroyer for new containers
* Fix warning for fnv1a on 32-bit arch
* Validator fixes for new containers

beast/strings/String.h

@@ -1215,6 +1215,14 @@ public:
     String convertToPrecomposedUnicode() const;
    #endif
 
+    template <class Hasher>
+    friend
+    void
+    hash_append (Hasher& h, String const& s)
+    {
+        h.append(s.text.getAddress(), s.text.sizeInBytes());
+    }
+
 private:
     //==============================================================================
     struct FromNumber { };