boxset image fixes

MediaBrowser.Controller/Entities/IHasMetadata.cs

@@ -30,6 +30,12 @@ namespace MediaBrowser.Controller.Entities
         /// <value>The date last saved.</value>
         DateTime DateLastSaved { get; set; }
 
+        /// <summary>
+        /// Gets or sets the date last refreshed.
+        /// </summary>
+        /// <value>The date last refreshed.</value>
+        DateTime DateLastRefreshed { get; set; }
+        
         /// <summary>
         /// Updates to repository.
         /// </summary>