edit-dialog: added stub code

The code added make the dialog show up. Probably anything else works,
but it's start to keep the project building while GcalManager migration
is finished and new GcalEditDialog is built.

src/gcal-edit-dialog.h

@@ -57,9 +57,8 @@ GType                gcal_edit_dialog_get_type                (void);
 
 GtkWidget*           gcal_edit_dialog_new                     (void);
 
-void                 gcal_edit_dialog_set_event               (GcalEditDialog *dialog,
-                                                               const gchar    *source_uid,
-                                                               const gchar    *event_uid);
+void                 gcal_edit_dialog_set_event_data          (GcalEditDialog *dialog,
+                                                               GcalEventData  *data);
 
 void                 gcal_edit_dialog_set_manager             (GcalEditDialog *dialog,
                                                                GcalManager    *manager);