support for .NET framework 3.5

Still have bugs

Net35/HandyControl_Net35/Shell/Standard/IPropertyStore.cs

@@ -0,0 +1,16 @@
+namespace Standard
+{
+    using System;
+    using System.Runtime.InteropServices;
+
+    [ComImport, Guid("886d8eeb-8cf2-4446-8d02-cdba1dbdcf99"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    internal interface IPropertyStore
+    {
+        uint GetCount();
+        Standard.PKEY GetAt(uint iProp);
+        void GetValue([In] ref Standard.PKEY pkey, [In, Out] PROPVARIANT pv);
+        void SetValue([In] ref Standard.PKEY pkey, PROPVARIANT pv);
+        void Commit();
+    }
+}
+