[gnome-mahjongg] Add a close button to the non-headerbar preferences dialog

[Michael Catanzaro <mcatanzaro src gnome org>]

commit d49d6af72935a7cbc6161f15ff76c4b3b148ebd3
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Sun Sep 28 18:24:39 2014 -0500

    Add a close button to the non-headerbar preferences dialog

 src/gnome-mahjongg.vala |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/gnome-mahjongg.vala b/src/gnome-mahjongg.vala
index eb2eb39..5a382dc 100644
--- a/src/gnome-mahjongg.vala
+++ b/src/gnome-mahjongg.vala
@@ -512,6 +512,9 @@ public class Mahjongg : Gtk.Application
 
         dialog_content_area.pack_start (grid, true, true, 0);
 
+        if (!dialogs_use_header)
+            preferences_dialog.add_button (_("_Close"), Gtk.ResponseType.CLOSE);
+
         preferences_dialog.show_all ();
     }