* elmo-pop3.el (elmo-folder-msgdb-create): Follow the API change.

* elmo-pop3.el (elmo-folder-msgdb-create): Follow the API change.
(elmo-pop3-msgdb-create-by-header): Ditto.
(elmo-pop3-msgdb-create-message): Ditto.

* elmo-shimbun.el (elmo-folder-msgdb-create): Ditto.

* elmo-sendlog.el (elmo-folder-msgdb-create): Ditto.

* elmo-nmz.el (elmo-folder-msgdb-create): Ditto.

* elmo-nntp.el (elmo-nntp-create-msgdb-from-overview-string): Ditto.
(elmo-folder-msgdb-create): Ditto.
(elmo-nntp-folder-msgdb-create): Ditto.
(elmo-nntp-msgdb-create-by-header): Ditto.
(elmo-nntp-msgdb-create-message): Ditto.
(elmo-folder-list-unreads): Define.

* elmo-pipe.el (elmo-folder-msgdb-create): Ditto.
(elmo-folder-append-messages): Ditto.
(elmo-folder-list-unreads): Define.
(elmo-folder-list-importants): Ditto.
(elmo-folder-list-answereds): Ditto.

* elmo-net.el (elmo-folder-list-unreads): Define.
(elmo-folder-list-importants): Ditto.
(elmo-folder-list-answereds): Ditto.
(elmo-folder-list-answereds-plugged): Ditto.
(elmo-folder-msgdb-create): Follow the API change.
(elmo-folder-msgdb-create-unplugged): Ditto.
(elmo-folder-unmark-answered): Define.
(elmo-folder-mark-as-answered-unplugged): Ditto.
(elmo-folder-unmark-answered-unplugged): Ditto.

* elmo-msgdb.el (elmo-msgdb-new-mark): New user option.
(elmo-msgdb-unread-uncached-mark): Ditto.
(elmo-msgdb-unread-cached-mark): Ditto.
(elmo-msgdb-read-uncached-mark): Ditto.
(elmo-msgdb-answered-cached-mark): Ditto.
(elmo-msgdb-answered-uncached-mark): Ditto.
(elmo-msgdb-important-mark): Ditto.
(elmo-msgdb-set-mark): Rewrite.
(elmo-msgdb-count-marks): Rewrite.
(elmo-msgdb-mark-alist-set): Abolish.
(elmo-msgdb-seen-list): Removed argument `seen-marks'.
(elmo-msgdb-add-msgs-to-seen-list): Likewise.

* elmo-multi.el (elmo-folder-check): Call elmo-folder-synchronize.
(elmo-folder-close): Define.
(elmo-folder-msgdb-create): Follow the API change.
(elmo-folder-list-unreads): Rewrite.
(elmo-folder-mark-as-important): Ditto.
(elmo-folder-unmark-important): Ditto.
(elmo-folder-mark-as-read): Ditto.
(elmo-folder-unmark-read): Ditto.
(elmo-folder-mark-as-answered): Define.
(elmo-folder-unmark-answered): Ditto.

* elmo-localdir.el (elmo-folder-msgdb-create): Follow the API change.
(elmo-folder-append-messages): Ditto.

* elmo-mark.el (elmo-folder-msgdb-create): Ditto.

* elmo-map.el (elmo-folder-list-unreads): Ditto.
(elmo-folder-list-importants): Ditto.

* elmo-maildir.el (elmo-folder-msgdb-create): Ditto.
(elmo-folder-append-messages): Ditto.