Revert "Revert "Hide polyfill.js from JSHint"" and use other way

This reverts commit ebb004d649c9c6e654fc6abc48fd2106315d4e0e.
Okay... if JSHint on Code Climate cannot recognize ignorance consistently, I'll tidy the codes.
Unwillingly remove non-ASCII characters for ship classifications

JSHint on CodeClimate persistently warn us against even non-ASCII characters "in comments"! We have no choice.