moving win10 app, bringing back uploader

clients/winuploader/Microbit.Uploader/SingleInstanceAppHelper.cs

@@ -0,0 +1,39 @@
+/****************************** Module Header ******************************\
+* Module Name:  SingleInstanceAppHelper.cs
+* Project:      CSWinFormSingleInstanceApp
+* Copyright (c) Microsoft Corporation.
+* 
+* The  sample demonstrates how to achieve the goal that only 
+* one instance of the application is allowed in Windows Forms application..
+* 
+* This source is subject to the Microsoft Public License.
+* See http://www.microsoft.com/en-us/openness/resources/licenses.aspx#MPL.
+* All other rights reserved.
+* 
+* THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, 
+* EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED 
+* WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
+\***************************************************************************/
+
+using System;
+using Microsoft.VisualBasic.ApplicationServices;
+using System.Windows.Forms;
+
+namespace Microsoft.MicroBit
+{
+    // We need to add Microsoft.VisualBasic reference to use
+    // WindowsFormsApplicationBase type.
+    class SingleInstanceApp : WindowsFormsApplicationBase 
+    {
+        public SingleInstanceApp()
+        {
+        }
+        public SingleInstanceApp(Form f)
+        {
+            // Set IsSingleInstance property to true to make the application 
+            base.IsSingleInstance = true;
+            // Set MainForm of the application.
+            this.MainForm = f;
+        }
+    }
+}