Refactoring of serialization versioning handling

- Removed 'version' field from serialize() method
- Handler classes - Binary(De)Serializer now have 'version' field
- Serialization versioning now uses named enum

Save compatibility with 1.4.X saves should be intact

lib/filesystem/ResourcePath.h

@@ -102,7 +102,7 @@ public:
 
 	void serializeJson(JsonSerializeFormat & handler);
 
-	template <typename Handler> void serialize(Handler & h, const int version)
+	template <typename Handler> void serialize(Handler & h)
 	{
 		h & type;
 		h & name;