Fix Tramp problems with multihops, and nc.

Fix Tramp problems with multihops, and nc.

* lisp/net/tramp-cache.el (tramp-get-file-property)
(tramp-set-file-property, tramp-flush-file-property)
(tramp-get-connection-property, tramp-set-connection-property)
(tramp-flush-connection-property): Remove hop from vector.

* lisp/net/tramp-gw.el (tramp-gw-process-filter): Ignore errors.

* lisp/net/tramp-sh.el (tramp-methods) <nc>: Separate STDERR.
(tramp-do-copy-or-rename-file-out-of-band): Increase timeout of
netstat to 60".
(tramp-sh-handle-start-file-process): Do not show hops in prompt.

* lisp/net/tramp.el (tramp-handle-file-name-as-directory)
(tramp-handle-file-name-directory, tramp-handle-file-remote-p):
Keep hop in result.

* test/automated/tramp-tests.el (tramp-test02-file-name-dissect):
Add hop tests.