add DisplayTitle to SubtitleStreamInfo

MediaBrowser.Model/Dlna/StreamInfo.cs

@@ -335,7 +335,8 @@ namespace MediaBrowser.Model.Dlna
                 Name = stream.Language ?? "Unknown",
                 Format = subtitleProfile.Format,
                 Index = stream.Index,
-                DeliveryMethod = subtitleProfile.Method
+                DeliveryMethod = subtitleProfile.Method,
+                DisplayTitle = stream.DisplayTitle
             };
 
             if (info.DeliveryMethod == SubtitleDeliveryMethod.External)

MediaBrowser.Model/Dlna/SubtitleStreamInfo.cs

@@ -7,6 +7,7 @@ namespace MediaBrowser.Model.Dlna
         public string Name { get; set; }
         public bool IsForced { get; set; }
         public string Format { get; set; }
+        public string DisplayTitle { get; set; }
         public int Index { get; set; }
         public SubtitleDeliveryMethod DeliveryMethod { get; set; }
         public bool IsExternalUrl { get; set; }