Added some favorites api calls

MediaBrowser.Model/DTO/DTOUserItemData.cs

@@ -0,0 +1,23 @@
+using ProtoBuf;
+
+namespace MediaBrowser.Model.DTO
+{
+    [ProtoContract]
+    public class DTOUserItemData
+    {
+        [ProtoMember(1)]
+        public float? Rating { get; set; }
+
+        [ProtoMember(2)]
+        public long PlaybackPositionTicks { get; set; }
+
+        [ProtoMember(3)]
+        public int PlayCount { get; set; }
+
+        [ProtoMember(4)]
+        public bool IsFavorite { get; set; }
+
+        [ProtoMember(5)]
+        public bool? Likes { get; set; }
+    }
+}