Bump version to 2.0.2.

Bump version to 2.0.2.
(tramp-methods): Rename methods invoking "ssh1" or "ssh2" to
longer names.  Use old names "sm1", "sm2" and so on for methods
invoking "ssh -1" or "ssh -2".
(tramp-multi-file-name-structure-separate): Typo, its name was set
to "tramp-file-name-structure-separate".  Trivial patch.  From
Steve Youngs <youngs@xemacs.org>.
(tramp-multi-sh-program): New variable.
(tramp-open-connection-multi): Use it.  Now you can use multi
methods from Windows (at least in principle).
(tramp-do-copy-or-rename-via-buffer): New function.
(tramp-do-copy-or-rename-file): Use it.  Change and simplify
logic.  Omit special case of invoking rcp directly to copy the
files.
(tramp-open-connection-su, tramp-multi-connect-telnet)
(tramp-multi-connect-rlogin, tramp-multi-connect-su)
(tramp-make-tramp-file-name, tramp-make-tramp-multi-file-name):
Use backticks in format-spec for brevity and to avoid
character/number confusion in XEmacs.