support for .NET framework 3.5

Still have bugs

Net35/HandyControl_Net35/Shell/Standard/DWMWA.cs

@@ -0,0 +1,21 @@
+namespace Standard
+{
+    using System;
+
+    internal enum DWMWA
+    {
+        ALLOW_NCPAINT = 4,
+        CAPTION_BUTTON_BOUNDS = 5,
+        DISALLOW_PEEK = 11,
+        EXCLUDED_FROM_PEEK = 12,
+        EXTENDED_FRAME_BOUNDS = 9,
+        FLIP3D_POLICY = 8,
+        FORCE_ICONIC_REPRESENTATION = 7,
+        HAS_ICONIC_BITMAP = 10,
+        NCRENDERING_ENABLED = 1,
+        NCRENDERING_POLICY = 2,
+        NONCLIENT_RTL_LAYOUT = 6,
+        TRANSITIONS_FORCEDISABLED = 3
+    }
+}
+