support for .NET framework 3.5

Still have bugs

Net35/HandyControl_Net35/Shell/Standard/CS.cs

@@ -0,0 +1,23 @@
+namespace Standard
+{
+    using System;
+
+    [Flags]
+    internal enum CS : uint
+    {
+        BYTEALIGNCLIENT = 0x1000,
+        BYTEALIGNWINDOW = 0x2000,
+        CLASSDC = 0x40,
+        DBLCLKS = 8,
+        DROPSHADOW = 0x20000,
+        GLOBALCLASS = 0x4000,
+        HREDRAW = 2,
+        IME = 0x10000,
+        NOCLOSE = 0x200,
+        OWNDC = 0x20,
+        PARENTDC = 0x80,
+        SAVEBITS = 0x800,
+        VREDRAW = 1
+    }
+}
+