Rename methods to better match new terminology and get rid of json data file.

2-6-client/lib/common/messages.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library pirate.messages;
 
-import 'dart:convert' show JSON;
-
+// This class is used to send data back and forth between the client and server.
+// It is automatically serialized and deserialized by the RPC package.
 class Pirate {
   String name;
   String appellation;
 
   // A message class must have a default constructor taking no arguments.
   Pirate();
 
   // It is fine to have other named constructors.
-  Pirate.fromJSON(String jsonString) {
-    Map storedName = JSON.decode(jsonString);
-    name = storedName['f'];
-    appellation = storedName['a'];
-  }
-
   Pirate.fromString(String pirateName) {
     var parts = pirateName.split(' the ');
     name = parts[0];
     appellation = parts[1];
   }
 
-  String get jsonString => JSON.encode({"f": name, "a": appellation});
-
   String toString() => name.isEmpty ? '' : '$name the $appellation';
 }