* elmo.el (elmo-folder-confirm-appends): Use `number-to-string'

* elmo.el (elmo-folder-confirm-appends): Use `number-to-string'
instead of `int-to-string'.
* elmo-archive.el (elmo-archive-message-fetch-internal)
(elmo-archive-folder-message-make-temp-files)
(elmo-archive-folder-append-buffer)
(elmo-folder-delete-messages-internal)
(elmo-archive-msgdb-create-entity)
(elmo-archive-msgdb-create-as-numlist-subr2): Ditto.
* elmo-util.el (elmo-cache-expire-by-age): Ditto.
* elmo-flag.el (elmo-global-flag-set-internal): Ditto.
* elmo-file.el (elmo-folder-message-make-temp-files): Ditto.
* elmo-imap4.el (elmo-imap4-make-number-set-list)
(elmo-folder-list-subfolders): Ditto.
* elmo-localdir.el (elmo-message-file-name)
(elmo-folder-message-make-temp-files)
(elmo-localdir-msgdb-create-entity)
(elmo-folder-append-messages-*-localdir)
(elmo-folder-pack-numbers): Ditto.
* elmo-maildir.el (elmo-folder-message-make-temp-files): Ditto.
* elmo-map.el (elmo-location-map-key): Ditto.
* elmo-nntp.el (elmo-nntp-folder-postfix)
(elmo-nntp-folder-list-subfolders)
(elmo-nntp-folder-msgdb-create): Ditto.