Tramp code cleanup

Tramp code cleanup

* lisp/net/tramp-adb.el
(tramp-adb-handle-directory-files-and-attributes): Use it.

* lisp/net/tramp-compat.el (tramp-compat-replace-regexp-in-region):
New defalias.

* lisp/net/tramp-crypt.el (tramp-crypt-do-encrypt-or-decrypt-file-name):
Fix root filename for cache.

* lisp/net/tramp-gvfs.el (tramp-gvfs-do-copy-or-rename-file):
Adapt check for proper remote command.

* lisp/net/tramp-sh.el (tramp-open-shell): Add sanity check for
shell prompt.
(tramp-get-ls-command): Check, that argument "--color=never" has
the intended effect.