support for .NET framework 3.5

Still have bugs

Net35/HandyControl_Net35/Shell/Standard/StockObject.cs

@@ -0,0 +1,21 @@
+namespace Standard
+{
+    using System;
+
+    internal enum StockObject
+    {
+        BLACK_BRUSH = 4,
+        BLACK_PEN = 7,
+        DEFAULT_PALETTE = 15,
+        DKGRAY_BRUSH = 3,
+        GRAY_BRUSH = 2,
+        HOLLOW_BRUSH = 5,
+        LTGRAY_BRUSH = 1,
+        NULL_BRUSH = 5,
+        NULL_PEN = 8,
+        SYSTEM_FONT = 13,
+        WHITE_BRUSH = 0,
+        WHITE_PEN = 6
+    }
+}
+