dxld-visual-line-mode.el

(setq-default
 visual-line-fringe-indicators
 '(left-curly-arrow right-curly-arrow))

(define-minor-mode dxld-visual-line-mode
  (if dxld-visual-line-mode
      (progn
        (visual-line-mode -1)
        (adaptive-wrap-prefix-mode -1)
        )
    (visual-line-mode 1)
    (adaptive-wrap-prefix-mode 1)
    )
  )

;; you can set adaptive-wrap-extra-indent to indent the continuation line a bit
;; more