bug#5392: 23.1.91; -Q becomes unknown if -displat is given.

[Chong Yidong]

> % emacs -Q -display :0
>
> A message appears in the minibuffer: Unknown option -Q.
> This is from command-line-1.  -Q has not been handeled since
> sort_args seems to always put -display before -Q (and others) handled
> in startup.el.  Thus the handling of option stops when -display is seen
> and -Q gets passed to command-line-1, which chould not happen.
>
> I don't understand the comment in emacs.c:
>   /* -d must come last before the options handled in startup.el.  */
>   { "-d", "--display", 60, 1 },
>   { "-display", 0, 60, 1 },
>
> Changing the prio to 6 cures this bug, but the comment seems to indicate
> this is the wrong thing to do.

The --display arg is a little funny, because it is handled partly in C
and partly in Lisp.  That's why it needs to have high priority.  I've
tweaked `command-line' to handle it specially.  Thanks for noticing
this.