Implement quoting the local part of a remote file name

Implement quoting the local part of a remote file name

* doc/emacs/files.texi (Quoted File Names):
* etc/NEWS: Mention quoting the local part of a remote file name.

* lisp/net/tramp.el (tramp-dissect-file-name): Check with
`tramp-tramp-file-p'.
(tramp-quoted-name-p, tramp-quote-name, tramp-unquote-name):
New defsubst.
(tramp-handle-substitute-in-file-name)
(tramp-handle-make-auto-save-file-name): Handle quoted files.
(tramp-shell-quote-argument): Unquote argument.

* lisp/net/tramp-sh.el (tramp-sh-handle-file-truename):
Handle quoted files.

* test/lisp/net/tramp-tests.el (tramp--test-expensive-test): New defvar.
(tramp--test-make-temp-name): New argument QUOTED.
(tramp-test01-file-name-syntax)
(tramp-test02-file-name-dissect)
(tramp-test04-substitute-in-file-name)
(tramp-test05-expand-file-name, tramp-test07-file-exists-p)
(tramp-test08-file-local-copy)
(tramp-test09-insert-file-contents)
(tramp-test10-write-region, tramp-test11-copy-file)
(tramp-test12-rename-file, tramp-test13-make-directory)
(tramp-test14-delete-directory, tramp-test15-copy-directory)
(tramp-test16-directory-files)
(tramp-test17-insert-directory)
(tramp-test18-file-attributes)
(tramp-test19-directory-files-and-attributes)
(tramp-test20-file-modes, tramp-test21-file-links)
(tramp-test22-file-times, tramp-test23-visited-file-modtime)
(tramp-test24-file-name-completion, tramp-test25-load)
(tramp-test26-process-file, tramp-test27-start-file-process)
(tramp-test28-shell-command, tramp-test30-vc-registered)
(tramp-test31-make-auto-save-file-name)
(tramp--test-check-files)
(tramp-test35-asynchronous-requests): Test also quoted file names.
(tramp--test-shell-command-to-string-asynchronously): Rename.
(tramp-test29-environment-variables): Use it.