Fix grep-like functions when running on a remote host

Fix grep-like functions when running on a remote host

* doc/lispref/processes.texi (Shell Arguments):
* etc/NEWS: Describe change in 'shell-quote-argument'.  Fix typos.

* lisp/subr.el (shell-quote-argument): New optional argument POSIX.

* lisp/progmodes/grep.el (grep-compute-defaults)
(grep-default-command, grep-expand-keywords, lgrep)
(rgrep-default-command): Use POSIX argument in
`shell-quote-argument'.  (Bug#54487)