fixes #280 - MB3 Local metadata fetcher for Music not seeing/using Artist Folder.jpg

MediaBrowser.Controller/Library/ILibraryManager.cs

@@ -144,12 +144,14 @@ namespace MediaBrowser.Controller.Library
         /// <param name="introProviders">The intro providers.</param>
         /// <param name="itemComparers">The item comparers.</param>
         /// <param name="prescanTasks">The prescan tasks.</param>
+        /// <param name="postscanTasks">The postscan tasks.</param>
         void AddParts(IEnumerable<IResolverIgnoreRule> rules, 
             IEnumerable<IVirtualFolderCreator> pluginFolders, 
             IEnumerable<IItemResolver> resolvers, 
             IEnumerable<IIntroProvider> introProviders, 
             IEnumerable<IBaseItemComparer> itemComparers,
-            IEnumerable<ILibraryPrescanTask> prescanTasks);
+            IEnumerable<ILibraryPrescanTask> prescanTasks,
+            IEnumerable<ILibraryPostScanTask> postscanTasks);
 
         /// <summary>
         /// Sorts the specified items.

MediaBrowser.Controller/Library/ILibraryPostScanTask.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace MediaBrowser.Controller.Library
+{
+    /// <summary>
+    /// An interface for tasks that run after the media library scan
+    /// </summary>
+    public interface ILibraryPostScanTask
+    {
+        /// <summary>
+        /// Runs the specified progress.
+        /// </summary>
+        /// <param name="progress">The progress.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns>Task.</returns>
+        Task Run(IProgress<double> progress, CancellationToken cancellationToken);
+    }
+}