Major rewrite due to changed D-Bus interface of GVFS 1.14.

Major rewrite due to changed D-Bus interface of GVFS 1.14.

* net/tramp-gvfs.el (top): Extend check for gvfs availability.
(tramp-gvfs-methods-mounttracker, tramp-gvfs-listmounts)
(tramp-gvfs-mountlocation, tramp-gvfs-mountlocation-signature):
New defconst.
(tramp-gvfs-file-name-handler-alist) [directory-files]:
[directory-files-and-attributes, file-exists-p, file-modes]: Use
Tramp default handler.
[file-acl, file-selinux-context, process-file, set-file-acl]:
[set-file-modes, set-file-selinux-context, shell-command]:
[start-file-process ]: Remove handler.
[verify-visited-file-modtime]: New handler.
(tramp-gvfs-dbus-string-to-byte-array)
(tramp-gvfs-dbus-byte-array-to-string): New defuns.  Replace all
calls of `dbus-string-to-byte-array' and
`tramp-gvfs-dbus-byte-array-to-string'.
(tramp-gvfs-handle-copy-file)
(tramp-gvfs-handle-delete-directory)
(tramp-gvfs-handle-delete-file, tramp-gvfs-handle-file-attributes)
(tramp-gvfs-handle-file-directory-p)
(tramp-gvfs-handle-file-executable-p)
(tramp-gvfs-handle-file-name-all-completions)
(tramp-gvfs-handle-file-readable-p)
(tramp-gvfs-handle-file-writable-p)
(tramp-gvfs-handle-insert-directory)
(tramp-gvfs-handle-insert-file-contents)
(tramp-gvfs-handle-make-directory, tramp-gvfs-handle-rename-file)
(tramp-gvfs-handle-set-visited-file-modtime)
(tramp-gvfs-handle-write-region): Rewrite.
(tramp-gvfs-handle-file-acl)
(tramp-gvfs-handle-file-selinux-context)
(tramp-gvfs-handle-process-file, tramp-gvfs-handle-set-file-acl)
(tramp-gvfs-handle-set-file-modes)
(tramp-gvfs-handle-set-file-selinux-context)
(tramp-gvfs-handle-shell-command)
(tramp-gvfs-handle-start-file-process)
(tramp-gvfs-handle-verify-visited-file-modtime): Remove defuns.
(tramp-gvfs-url-file-name): Do not use `file-truename', we work
over the symlinks.  Fix user handling.
(top, tramp-gvfs-handler-mounted-unmounted): Handle different names
of the D-Bus signals.
(tramp-gvfs-connection-mounted-p): Handle different names of the
D-Bus methods.
(tramp-gvfs-mount-spec-entry): New defun.
(tramp-gvfs-mount-spec): Use it.
(tramp-gvfs-maybe-open-connection): Check, that in case of "smb"
there is a share name.  Handle different names of the D-Bus
signals and methods.
(tramp-gvfs-maybe-open-connection): Set connection properties
needed for `tramp-check-cached-permissions'.
(tramp-gvfs-send-command): Apply `tramp-gvfs-maybe-open-connection'.
Return t or nil.

* net/tramp.el (tramp-backtrace): Move up.
(tramp-error): Apply a backtrace into the debug buffer when
`tramp-verbose > 9.
(tramp-file-mode-type-map, tramp-file-mode-from-int)
(tramp-file-mode-permissions, tramp-get-local-uid)
(tramp-get-local-gid, tramp-check-cached-permissions): Move from
tramp-sh.el.

* net/tramp-sh.el (tramp-file-mode-type-map)
(tramp-check-cached-permissions, tramp-file-mode-from-int)
(tramp-file-mode-permissions, tramp-get-local-uid)
(tramp-get-local-gid): Move to tramp.el.