New command tramp-revert-buffer-with-sudo

New command tramp-revert-buffer-with-sudo

* doc/misc/tramp.texi (Ad-hoc multi-hops):
Document tramp-file-name-with-method and tramp-revert-buffer-with-sudo.

* etc/NEWS: New command tramp-revert-buffer-with-sudo.

* lisp/net/tramp-cmds.el (dired-advertise, dired-unadvertise): Declare.
(tramp-dired-buffer-p, tramp-remote-process-p): Rename.
(tramp-file-name-with-method): New defcustom.
(tramp-file-name-with-sudo, tramp-revert-buffer-with-sudo): New defuns.