Merge branch 'ja/clean-confirm-i18n'

The prompt string "remove?" used when "git clean -i" asks the user
if a path should be removed was localizable, but the code always
expects a substring of "yes" to tell it to go ahead.  Always show
[y/N] as part of this prompt to hint that the answer is not (yet)
localized.

* ja/clean-confirm-i18n:
  Add hint interactive cleaning

diff --cc builtin/clean.c
Simple merge