fixed: missing serialization for rsval in DeckItem

this broke ActionX in parallel

opm/parser/eclipse/Deck/DeckItem.hpp

@@ -135,6 +135,7 @@ namespace Opm {
             serializer(dval);
             serializer(ival);
             serializer(sval);
+            serializer.vector(rsval);
             serializer.vector(uval);
             serializer(type);
             serializer(item_name);

opm/parser/eclipse/Utility/Typetools.hpp

@@ -44,6 +44,12 @@ public:
         return std_strings;
     }
 
+    template<class Serializer>
+    void serializeOp(Serializer& serializer)
+    {
+      serializer(static_cast<std::string&>(*this));
+    }
+
 };
 
 inline std::string tag_name( type_tag x ) {