* elmo2.el (elmo-move-msgs): Bind

* elmo2.el (elmo-move-msgs): Bind
elmo-inhibit-display-retrieval-progress as t while moving messages.

* elmo-vars.el (elmo-display-retrieval-progress-threshold):
New variable.
(elmo-inhibit-display-retrieval-progress): Ditto.

* elmo-pop3.el (elmo-pop3-process-filter): Use elmo-display-progress
for retrieval progress;
Don't display progress when total buffer size is smaller than
elmo-display-retrieval-progress-threshold.
(elmo-pop3-read-msg): Don't display progress when
elmo-inhibit-display-retrieval-progress is non-nil;
Remove progress bar after retrieval.

* elmo-imap4.el (elmo-imap4-find-next-line): Use elmo-display-progress
for retrieval progress;
Don't display progress when literal size is smaller than
elmo-display-retrieval-progress-threshold.
(elmo-imap4-read-msg): Don't display progress when
elmo-inhibit-display-retrieval-progress is non-nil;
Remove progress bar after retrieval.
* elmo-imap4.el (elmo-imap4-read-part): Ditto.