Added a completely separate DTOBaseItem to remove the ApiBaseItemWrapper mess and shrink json output size.

MediaBrowser.Model/Entities/UserItemData.cs

@@ -0,0 +1,20 @@
+using System;
+
+namespace MediaBrowser.Model.Entities
+{
+    public class UserItemData
+    {
+        public UserItemRating Rating { get; set; }
+
+        public long PlaybackPositionTicks { get; set; }
+
+        public int PlayCount { get; set; }
+    }
+
+    public enum UserItemRating
+    {
+        Likes,
+        Dislikes,
+        Favorite
+    }
+}