[glibmm] HelperList: Deprecate this.

[Murray Cumming <murrayc src gnome org>]

commit 08c6cc2ca8dfdab8c1294bc925ea31df0b6ff8ff
Author: Murray Cumming <murrayc murrayc com>
Date:   Mon Jun 29 08:27:16 2015 +0200

    HelperList: Deprecate this.
    
    Because nothing uses it anymore. See the previous commit about GP_LIST.

 glib/glibmm/helperlist.h |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)
---
diff --git a/glib/glibmm/helperlist.h b/glib/glibmm/helperlist.h
index dfdc070..1955be1 100644
--- a/glib/glibmm/helperlist.h
+++ b/glib/glibmm/helperlist.h
@@ -22,12 +22,19 @@
  * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#ifndef GLIBMM_DISABLE_DEPRECATED
+
 #include <glibmm/containers.h>
 
 namespace Glib
 {
 
 // This class has some pure virtual methods which need to be implemented by derived classes.
+
+/**
+ * @deprecated This class should no longer be necessary. It has not been used
+ * by glibmm or gtkmm since gtkmm-2.4.
+ */
 template< typename T_Child, typename T_CppElement, typename T_Iterator >
 class HelperList
 {
@@ -162,5 +169,7 @@ protected:
 
 } /* namespace Glib */
 
+#endif //GLIBMM_DISABLE_DEPRECATED
+
 #endif /* _GLIBMM_HELPERLIST_H */