Added and fixed WorkItemsGroupDemoMono

Also fixed Performance Counter which doesn't work on Mono

WorkItemsGroupDemo/Program.cs

@@ -11,6 +11,8 @@ namespace WorkItemsGroupDemo
         [STAThread]
         public static void Main()
         {
+            Form1.Init();
+
             Application.EnableVisualStyles();
             Application.SetCompatibleTextRenderingDefault(false);
             Application.Run(new Form1());