Added Prism to example, Added ability to filter files and minor bugfixes

Katteker.Gui/UserInterface.cs

@@ -1,4 +1,5 @@
-using System.Linq;
+using System;
+using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using System.Windows.Forms;
@@ -12,6 +13,7 @@ namespace Katteker
     public static class UserInterface
     {
         private static UpdateManager _manager;
+        private static Action _restartApp;
 
         /// <summary>
         ///     Checks for Updates.
@@ -38,6 +40,7 @@ namespace Katteker
             }
 
             var releases = (await _manager.CheckForUpdateAsync().ConfigureAwait(false)).ToArray();
+            _restartApp = () => _manager.RestartApp();
             if (releases.Any() || !isStartup)
             {
                 var thread = new Thread(ThreadProcess);
@@ -49,13 +52,13 @@ namespace Katteker
 
         private static void ThreadProcess(object argument)
         {
-            var entry = (ReleaseEntry) argument;
+            var entry = argument as ReleaseEntry;
             using (var window = new UpdateWindow(_manager, entry))
             {
                 var dialogResult = window.ShowDialog();
                 if (dialogResult == DialogResult.OK)
                 {
-                    _manager.RestartApp();
+                    _restartApp?.Invoke();
                 }
             }
         }