support for .NET framework 3.5

Still have bugs

Net35/HandyControl_Net35/Shell/Standard/IEnumIDList.cs

@@ -0,0 +1,17 @@
+namespace Standard
+{
+    using System;
+    using System.Runtime.InteropServices;
+
+    [ComImport, Guid("000214F2-0000-0000-C000-000000000046"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    internal interface IEnumIDList
+    {
+        [PreserveSig]
+        Standard.HRESULT Next(uint celt, out IntPtr rgelt, out int pceltFetched);
+        [PreserveSig]
+        Standard.HRESULT Skip(uint celt);
+        void Reset();
+        void Clone([MarshalAs(UnmanagedType.Interface)] out Standard.IEnumIDList ppenum);
+    }
+}
+