エコーエリアや *Messages* バッファにメッセージを表示させたくない ref: http://qiita.com/itiut@github/items/d917eafd6ab255629346

file0.txt

(defmacro with-suppressed-message (&rest body)
  "Suppress new messages temporarily in the echo area and the `*Messages*' buffer while BODY is evaluated."
  (declare (indent 0))
  (let ((message-log-max nil))
    `(with-temp-message (or (current-message) "") ,@body)))

file1.txt

(with-suppressed-message
  (message "foo")
  (message "bar")
  (message "baz"))

file2.txt

(run-with-idle-timer 30 t '(lambda ()
                             (with-suppressed-message (recentf-save-list))))