toggling diff-auto-refine

[Thien-Thi Nguyen]

how about replacing the `(defcustom diff-auto-refine ...)' with:

(define-minor-mode diff-auto-refine
  "Automatically highlight changes in detail as the user visits hunks."
  :group 'diff-mode :init-value nil :lighter " Auto-Refine"
  (when diff-auto-refine
    (condition-case-no-debug nil (diff-refine-hunk) (error nil))))

i find this useful for cruising around unwieldy diffs where there is a
mix of quickly refined hunks and slowly refined hunks.

thi