bug#58102: [PATCH] Do not use -Q when calculating Emacs site-lisp directory

[Karl Berry]

Hi again Richard,

    * XEmacs doesn't support -Q and ignores it; and
    * the different releases of GNU Emacs handle it differently,
      or not at all.

Thanks. I applied it.

    From this testing I think the existing usage of '--no-site-file'

It seemed too confusing to me to use --no-site-file in the documentation
when the other options (-batch, -eval) use single dashes. So I changed
it. And I changed the code in lispdir.m4 to match. OTOH, I kept the code
in lisp.am that's using double dashes (--batch --no-site-file) since
really, both should work, and are assumed to work, so might as well use
both.

It is standard behavior in Emacs (and many other programs) for long
options to be accepted with both single and double dashes. The --help
message for emacs says:

  You can generally also specify long option names with a single -; for
  example, -batch as well as --batch.

Maybe the xemacs help msg or doc also says that? It would have been
quite strange/gratuitous for them to change that.  Documentation often
arbitrarily uses one or two dashes. --thanks, karl.