* elmo-pop3.el (elmo-pop3-debug): New variable.

* elmo-pop3.el (elmo-pop3-debug): New variable.
(elmo-pop3-debug-inhibit-logging): Ditto.
(elmo-pop3-debug): New function.
(elmo-pop3-send-command): Call elmo-pop3-debug.
(elmo-pop3-read-response): Added keep-lock optional argument;
Don't unlock if keep-lock is non-nil.
(elmo-pop3-process-filter): Call elmo-pop3-debug.
(elmo-network-authenticate-session): Bind
elmo-pop3-debug-inhibit-logging as t.
(elmo-network-setup-session): Call elmo-pop3-read-response with
keep-lock argument.
(elmo-pop3-read-msg): Ditto.
(elmo-pop3-locked-p): Call elmo-pop3-debug.
(elmo-pop3-read-body): Call elmo-pop3-unlock.
(elmo-network-initialize-session): Call elmo-pop3-lock.
(elmo-folder-close-internal): Don't clear location-alist slot.
(elmo-folder-check): Clear location-alist slot.