Document remote file name syntax change

Document remote file name syntax change

* doc/emacs/files.texi (Remote Files, Quoted File Names):
* doc/misc/org.texi (dir): Change examples to use a method.

* doc/misc/tramp.texi (Top) [trampf]: Remove macro.  Add
`Testing' menu entry.
(History): Fix typos.  Mention syntax change.
(Configuration, Default Host, File name Syntax)
(File name completion, Frequently Asked Questions):
Change examples to use a method.
(External methods, Default Host, Multi-hops, Remote processes):
Fix typos.
(Default Method): Mention pseudo method "-".
(External packages): Rewrite intention of `non-essential'.

* etc/NEWS: Mark recent Tramp entries as documented.