* net/tramp.el (tramp-completion-mode-p): Rename from

* net/tramp.el (tramp-completion-mode-p): Rename from
`tramp-completion-mode'. Revert logic, check `return', `newline'
and such alike. Packages like Icicles tend to use other completion
characters but `tab' and `space' only.
(top): Require cl.el, when `copy-tree' is not available otherwise.

* net/tramp-vc.el (tramp-vc-user-login-name): Get argument by
`ad-get-arg'.  Use `vc-find-version' instead of `process-file' to check
whether we have a new enough vc that doesn't need the defadvice.