_GtkFileChooserButtonPrivate: Added has_title flag so we can remember

_GtkFileChooserButtonPrivate: Added has_title flag so we can remember

2006-04-19  Murray Cumming  <murrayc@murrayc.com>

        * gtk/gtkfilechooserbutton.c: _GtkFileChooserButtonPrivate:
        Added has_title flag so we can remember whether a title has
        been set.
        (gtk_file_chooser_button_constructor): If no title has been
        set then set it to the default title. This means that the
        default title will be used if the dialog was instantiated with
        g_object_new(), without using the gtk_file_chooser_button_new()
        convenience function. This helps language bindings.
        (gtk_file_chooser_button_set_property): Set has_title when
        setting the title.