Change ItemId to Guid like all the others

MediaBrowser.Controller/Providers/RemoteSearchQuery.cs

@@ -1,3 +1,5 @@
+using System;
+
 namespace MediaBrowser.Controller.Providers
 {
     public class RemoteSearchQuery<T>
@@ -5,7 +7,7 @@ namespace MediaBrowser.Controller.Providers
     {
         public T SearchInfo { get; set; }
 
-        public string ItemId { get; set; }
+        public Guid ItemId { get; set; }
 
         /// <summary>
         /// If set will only search within the given provider

MediaBrowser.Providers/Manager/ProviderManager.cs

@@ -156,7 +156,7 @@ namespace MediaBrowser.Providers.Manager
 
             }).ConfigureAwait(false))
             {
-                // Workaround for tvheadend channel icons	
+                // Workaround for tvheadend channel icons
                 // TODO: Isolate this hack into the tvh plugin
                 if (string.IsNullOrEmpty(response.ContentType))
                 {