Upgraded Protobuf, and added api support for it

MediaBrowser.Model/Entities/Video.cs

@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using ProtoBuf;
 
 namespace MediaBrowser.Model.Entities
 {
@@ -17,20 +18,38 @@ namespace MediaBrowser.Model.Entities
         public string Codec { get; set; }
     }
 
+    [ProtoContract]
     public class AudioStream
     {
+        [ProtoMember(1)]
         public string Codec { get; set; }
+
+        [ProtoMember(2)]
         public string Language { get; set; }
+
+        [ProtoMember(3)]
         public int BitRate { get; set; }
+
+        [ProtoMember(4)]
         public int Channels { get; set; }
+
+        [ProtoMember(5)]
         public int SampleRate { get; set; }
+
+        [ProtoMember(6)]
         public bool IsDefault { get; set; }
     }
 
+    [ProtoContract]
     public class SubtitleStream
     {
+        [ProtoMember(1)]
         public string Language { get; set; }
+
+        [ProtoMember(2)]
         public bool IsDefault { get; set; }
+
+        [ProtoMember(2)]
         public bool IsForced { get; set; }
     }