[gtkmm] Window: Add the keys_changed signal.

[Murray Cumming <murrayc src gnome org>]

commit b75b52bda5fd7b95108480abd2c34c84d6df4730
Author: Murray Cumming <murrayc murrayc com>
Date:   Tue Sep 23 12:58:29 2014 +0200

    Window: Add the keys_changed signal.
    
    Without a default handler, to preserve ABI.

 gtk/src/window.hg |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/gtk/src/window.hg b/gtk/src/window.hg
index a42412b..86993ea 100644
--- a/gtk/src/window.hg
+++ b/gtk/src/window.hg
@@ -150,6 +150,9 @@ public:
 
   _WRAP_SIGNAL(void set_focus(Widget* focus), "set_focus")
 
+  //TODO: Remove no_default_handler when we can break ABI:
+  _WRAP_SIGNAL(void keys_changed(), "keys_changed", no_default_handler)
+
   //Keybinding signals:
   _IGNORE_SIGNAL("activate_focus")
   _IGNORE_SIGNAL("activate_default")