[glibmm] Add a TODO comment for C++11.

[Murray Cumming <murrayc src gnome org>]

commit 33736468e9df02e7f0fe856c0f69ee2e20a693fd
Author: Murray Cumming <murrayc murrayc com>
Date:   Fri Jan 17 09:16:06 2014 +0100

    Add a TODO comment for C++11.

 glib/glibmm/utility.h |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/glib/glibmm/utility.h b/glib/glibmm/utility.h
index f5aa2a8..6e5319b 100644
--- a/glib/glibmm/utility.h
+++ b/glib/glibmm/utility.h
@@ -56,6 +56,7 @@ namespace Glib
 
 // These are used by gtkmmproc-generated type conversions:
 
+// TODO: Replace this with std::unique_ptr?
 // Helper to deal with memory allocated
 // by GLib functions in an exception-safe manner.
 template <typename T>