CHANGELOG translate into Japanese

from 7382a6e6a66d3f80da955ebbcd82250f99321900 and 233489ddfe4698b24dfcdc1daf3ca15bc880e4b1
Merge pull request #933 from ykzts/changelog-translate-ja-7382a6e6a66d3f80da955ebbcd82250f99321900-and-233489ddfe4698b24dfcdc1daf3ca15bc880e4b1

CHANGELOG translate into Japanese