add Japanese translation
Merge branch 'v4' of https://github.com/beerbong/com_beerbong_zipinst into v4
Merge branch 'v4' of https://github.com/beerbong/com_beerbong_zipinst into v4
Merge branch 'v4' of https://github.com/beerbong/com_beerbong_zipinst into v4
Merge pull request #19 from hayashikejinan/v4

add Japanese translation & fix