[hyena] build: Fix compilation under Mono 2.8

[Alexander Kojevnikov <alexk src gnome org>]

commit 359d12855945646a2a4b8296d466f672d3dcee95
Author: Alexander Kojevnikov <alexander kojevnikov com>
Date:   Sat Oct 16 15:46:50 2010 +1100

    build: Fix compilation under Mono 2.8

 Hyena.Gui/Hyena.Data.Gui/ColumnHeaderCellText.cs |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/Hyena.Gui/Hyena.Data.Gui/ColumnHeaderCellText.cs b/Hyena.Gui/Hyena.Data.Gui/ColumnHeaderCellText.cs
index e45a54a..167cd2f 100644
--- a/Hyena.Gui/Hyena.Data.Gui/ColumnHeaderCellText.cs
+++ b/Hyena.Gui/Hyena.Data.Gui/ColumnHeaderCellText.cs
@@ -36,7 +36,7 @@ namespace Hyena.Data.Gui
 {
     public class ColumnHeaderCellText : ColumnCellText, IHeaderCell
     {
-        public delegate Column DataHandler ();
+        public new delegate Column DataHandler ();
 
         private DataHandler data_handler;
         private bool has_sort;