Upgraded Protobuf, and added api support for it

MediaBrowser.Model/DTO/DTOUser.cs

@@ -0,0 +1,18 @@
+using System;
+using ProtoBuf;
+
+namespace MediaBrowser.Model.DTO
+{
+    [ProtoContract]
+    public class DTOUser
+    {
+        [ProtoMember(1)]
+        public string Name { get; set; }
+
+        [ProtoMember(2)]
+        public Guid Id { get; set; }
+
+        [ProtoMember(3)]
+        public bool HasImage { get; set; }
+    }
+}