Add api to ibus for retreiving unused config values.

src/ibusconfigservice.h

 /* vim:set et sts=4: */
 /* ibus - The Input Bus
  * Copyright (C) 2008-2010 Peng Huang <shawn.p.huang@gmail.com>
  * Copyright (C) 2008-2010 Red Hat, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 164 matching lines @@
                                IBusError           **error);
     gboolean    (* get_value) (IBusConfigService    *config,
                                const gchar          *section,
                                const gchar          *name,
                                GValue               *value,
                                IBusError           **error);
     gboolean    (* unset)     (IBusConfigService    *config,
                                const gchar          *section,
                                const gchar          *name,
                                IBusError           **error);
+    gboolean    (* get_unused)(IBusConfigService    *config,
+                               GValue               *unread,
+                               GValue               *unwritten,
+                               IBusError           **error);
 
     /*< private >*/
     /* padding */
     gpointer pdummy[13];
 };
 
 GType                ibus_config_service_get_type   (void);
 
 /**
  * ibus_config_service_new:
@@ skipping 15 matching lines @@
  * by sending a "ValueChanged" message to IBus service.
  */
 void                 ibus_config_service_value_changed
                                                     (IBusConfigService  *config,
                                                      const gchar        *section,
                                                      const gchar        *name,
                                                      const GValue       *value);
 
 G_END_DECLS
 #endif
-