Synch up with main trunk and following:

Synch up with main trunk and following:

* wl-summary.el (wl-summary-rescan): Follow the changes in wl-score API.
(wl-summary-sync-update): Ditto.

* wl-score.el (wl-score-get-score-alist): Changed argument.
(wl-summary-rescore-msgs): Likewise.
(wl-summary-score-headers): Likewise.
(wl-score-headers): Likewise;
Use elmo-folder-do-each-message-entity, etc.
(wl-summary-score-effect): Follow the changes above.
(wl-summary-rescore): Ditto.
(wl-score-get-latest-msgs): Follow the changes in elmo-msgdb API.
(wl-score-get-overview): Abolish.

* wl-summary.el (wl-summary-default-from): Follow the API change in
elmo-msgdb.
(wl-summary-count-unread): Ditto.
(wl-summary-detect-mark-position): Ditto.
(wl-summary-overview-entity-compare-by-date): Ditto.
(wl-summary-overview-entity-compare-by-number): Ditto.
(wl-summary-overview-entity-compare-by-from): Ditto.
(wl-summary-overview-entity-compare-by-subject): Ditto.
(wl-summary-get-list-info): Ditto.
(wl-summary-rescan): Ditto.
(wl-summary-jump-to-msg-by-message-id): Ditto.
(wl-summary-sync-update): Ditto; Removed comment.
(wl-summary-insert-thread-entity): Renamed to wl-summary-insert-thread.
(wl-summary-insert-message): Use wl-summary-insert
(wl-summary-insert-sequential): Changed argument msgdb to folder.
(wl-summary-insert-headers): Changed argument overview to folder.
(wl-summary-search-by-subject): Likewise.
(wl-summary-insert-thread): Renamed from
wl-summary-insert-thread-entity and changed argument msgdb to folder.

* wl-folder.el (wl-folder-check-one-entity): Treat elmo-imap4-bye-error
too.

* wl-fldmgr.el (wl-add-entity-sub): Use elmo-string-member instead of
wl-string-member.

* elmo.el (elmo-folder-list-messages): Redefine as a luna method.
(elmo-folder-list-message-entities): New API.
(elmo-message-entity): Ditto.
(elmo-message-entity-parent): Ditto.
(elmo-folder-do-each-message-entity): Ditto.
(elmo-message-entity-number): Ditto.
(elmo-message-entity-field): Ditto.
(elmo-message-entity-set-field): Ditto.
(elmo-folder-count-flags): Ditto.
(elmo-folder-length): Ditto.

* elmo-util.el (elmo-get-hash-val): Check whether hashtable is nil or
not.

* elmo-msgdb.el (elmo-msgdb-list-messages): New function.
(elmo-msgdb-count-marks): Abolish.
(elmo-msgdb-make-entity): Ditto.
(elmo-msgdb-do-each-entity): Ditto.
(elmo-msgdb-message-entity): New inline function.
(elmo-msgdb-message-entity-field): Ditto.
(elmo-msgdb-message-entity-set-field): Ditto.
(elmo-msgdb-make-message-entity): New function.