[gnome-mahjongg] Use a header bar on the preferences dialog

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 029df2420b11cc1d78a886d1403eeed4a94e206d
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Sun May 11 17:15:29 2014 -0500

    Use a header bar on the preferences dialog

 src/gnome-mahjongg.vala |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)
---
diff --git a/src/gnome-mahjongg.vala b/src/gnome-mahjongg.vala
index 695d437..79ddfaf 100644
--- a/src/gnome-mahjongg.vala
+++ b/src/gnome-mahjongg.vala
@@ -351,9 +351,8 @@ public class Mahjongg : Gtk.Application
 
         preferences_dialog = new Gtk.Dialog.with_buttons (_("Mahjongg Preferences"),
                                                    window,
-                                                   Gtk.DialogFlags.DESTROY_WITH_PARENT,
-                                                   _("_Close"),
-                                                   Gtk.ResponseType.CLOSE, null);
+                                                   Gtk.DialogFlags.USE_HEADER_BAR,
+                                                   null);
         preferences_dialog.set_border_width (5);
         var dialog_content_area = (Gtk.Box) preferences_dialog.get_content_area ();
         dialog_content_area.set_spacing (2);