use shortcut manager for the main help menu * main_window.cc (add_action): new parameter for the signal receiver; (construct_help_menu): use add_action for the actions of the menu; (construct_documentation_menu): use add_action for the actions of the menu; (set_global_shortcuts): set/unset shortcuts * main-window.h: actions are class variables, add_action with new parameter * shortcut-manager.cc (do_init_data): initialize the shortcuts in the help menu

function s = get (p, f)
  if (nargin == 1)
    s.poly = p.poly;
  elseif (nargin == 2)
    if (ischar (f))
      switch (f)
        case "poly"
          s = p.poly;
        otherwise
          error ("get: invalid property %s", f);
      endswitch
    else
      error ("get: expecting the property to be a string");
    endif
  else
    print_usage ();
  endif
endfunction