Improve compatibility with older Emacsen, and XEmacs.

Improve compatibility with older Emacsen, and XEmacs.

* net/tramp.el (tramp-find-method, tramp-find-user): Call `propertize'
only if it is bound.  It isn't for XEmacs.
(with-tramp-progress-reporter): Do not let-bind `result'.  This
yields to scoping errors in XEmacs.
(tramp-handle-make-auto-save-file-name): New function, moved from
tramp-sh.el.

* net/tramp-adb.el (tramp-adb-file-name-handler-alist): Add handler
for `make-auto-save-file-name'.
(tramp-adb--gnu-switches-to-ash): Use
`tramp-compat-replace-regexp-in-string'.

* net/tramp-cache.el (tramp-cache-print): Call
`substring-no-properties' only if it is bound.  It isn't for XEmacs.

* net/tramp-cmds.el (tramp-bug): Call `propertize' only if it is
bound.  It isn't for XEmacs.

* net/tramp-compat.el (tramp-compat-copy-file): Catch
`wrong-number-of-arguments' error.
(tramp-compat-replace-regexp-in-string): New defun.

* net/tramp-gvfs.el (tramp-gvfs-file-name-handler-alist): Add handler
for `make-auto-save-file-name'.
(tramp-gvfs-handle-copy-file): Use `tramp-compat-funcall' for
`copy-file'.
(tramp-gvfs-file-gvfs-monitor-file-process-filter)
(tramp-gvfs-file-name): Use `tramp-compat-replace-regexp-in-string'.
(tramp-synce-list-devices): Use `push' instead of `pushnew'.

* net/tramp-gw.el (tramp-gw-open-network-stream): Use
`tramp-compat-replace-regexp-in-string'.

* net/tramp-sh.el (tramp-sh-file-name-handler-alist): Call
`tramp-handle-make-auto-save-file-name'.
(tramp-sh-handle-make-auto-save-file-name): Move to tramp.el.
(tramp-sh-file-gvfs-monitor-dir-process-filter)
(tramp-sh-file-inotifywait-process-filter): Use
`tramp-compat-replace-regexp-in-string'.
(tramp-compute-multi-hops): Use `push' instead of `pushnew'.

* net/tramp-smb.el (tramp-smb-file-name-handler-alist): Add handler
for `make-auto-save-file-name'.
(tramp-smb-handle-copy-directory): Call
`tramp-compat-replace-regexp-in-string'.
(tramp-smb-get-file-entries): Use `push' instead of `pushnew'.
(tramp-smb-handle-copy-file): Improve error message.
(tramp-smb-handle-rename-file): Rename directly only in case
`newname' does not exist yet.  This is a restriction of smbclient.
(tramp-smb-maybe-open-connection): Rerun the function only when
`auth-sources' is non-nil.