Originally Posted by Adam B.
gtk_window_set_type_hint (body->main_window, GDK_WINDOW_TYPE_HINT_DIALOG);
Adding the above in line 51 or so of src/b_main.c should do the trick.
Oh, I was searching the GTK Reference Manual.
Cool, that's so easy.
I will try it at home later. Working Day is over here in Germany.