support for .NET framework 3.5

Still have bugs

Net35/HandyControl_Net35/Shell/Standard/IObjectWithAppUserModelId.cs

@@ -0,0 +1,14 @@
+namespace Standard
+{
+    using System;
+    using System.Runtime.InteropServices;
+
+    [ComImport, Guid("36db0196-9665-46d1-9ba7-d3709eecf9ed"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    internal interface IObjectWithAppUserModelId
+    {
+        void SetAppID([MarshalAs(UnmanagedType.LPWStr)] string pszAppID);
+        [return: MarshalAs(UnmanagedType.LPWStr)]
+        string GetAppID();
+    }
+}
+