Another attempt at ProtoBuf serialization of Inventory

LibreMetaverse.Types/UUID.cs

@@ -26,6 +26,7 @@
 
 using System;
 using System.Security.Cryptography;
+using ProtoBuf;
 
 namespace OpenMetaverse
 {
@@ -34,9 +35,11 @@ namespace OpenMetaverse
     /// Life networking protocol
     /// </summary>
     [Serializable]
+    [ProtoContract]
     public struct UUID : IComparable<UUID>, IEquatable<UUID>
     {
         /// <summary>The System.Guid object this struct wraps around</summary>
+        [ProtoMember(1)]
         public Guid Guid { get; set; }
 
         #region Constructors