* elmo.el (elmo-folder-search): Defined. Fixed docstring.

* elmo.el (elmo-folder-search): Defined. Fixed docstring.
(elmo-message-match-condition): New method.
(elmo-folder-search-fast): New inline function.
(elmo-msgdb-search): Removed.

* elmo-filter.el (elmo-folder-msgdb-create): Create from msgdb of
target folder if it is unplugged.
(elmo-folder-list-messages-internal): Return t if target folder is
unplugged and itself is persistent; In this case, use list be
searched already.

* elmo-msgdb.el (elmo-msgdb-search-internal): Removed.
(elmo-msgdb-search-internal-primitive): Ditto.
(elmo-msgdb-match-condition): New function.
(elmo-msgdb-match-condition-primitive): Ditto.

* elmo-util.el (elmo-filter-condition-p): New macro.

* elmo-cache.el (elmo-folder-search): Removed.

* elmo-localdir.el (elmo-folder-search): Ditto.

* elmo-maildir.el (elmo-folder-search): Ditto.

* elmo-mark.el (elmo-folder-search): Ditto.

* elmo-nmz.el (elmo-folder-search): Ditto.

* elmo-sendlog.el (elmo-folder-search): Ditto.

* elmo-shimbun.el (elmo-folder-search): Ditto.

* elmo-imap4.el (elmo-folder-search): Call method of parent class
if folder is unplugged.

* elmo-nntp.el (elmo-folder-search): Likewise.
(elmo-nntp-search-internal): New function.