Set AWT/WinForms thread as Background to stop it from keeping the process alive.

awt/toolkit.cs

@@ -158,7 +158,7 @@ namespace ikvm.awt
 				Thread thread = new Thread(new ThreadStart(MessageLoop));
 				thread.ApartmentState = ApartmentState.STA;
 				thread.Name = "IKVM AWT WinForms Message Loop";
-				//thread.IsBackground = true;
+				thread.IsBackground = true;
 				thread.Start();
 				// TODO don't use polling...
 				while(bogusForm == null && thread.IsAlive)