In Tramp, use scp "-T" argument if available
* lisp/net/tramp-sh.el (tramp-scp-strict-file-name-checking): New defvar.
(tramp-scp-strict-file-name-checking): New defun.
(tramp-do-copy-or-rename-file-out-of-band): Use it.
(tramp-methods) <scp, scpx>: Use "%x".
(tramp-make-copy-program-file-name): Use local quoting.
(tramp-sh-handle-make-process): Don't call
`tramp-maybe-open-connection', this happens implicitly by
`tramp-send-command'.
* lisp/net/tramp.el (tramp-methods): Adapt docstring.
* test/lisp/net/tramp-tests.el (tramp-test40-special-characters)
(tramp-test40-special-characters-with-stat)
(tramp-test40-special-characters-with-perl)
(tramp-test40-special-characters-with-ls): Don't skip for
`tramp--test-windows-nt-and-scp-p'.