refined the translation of the word "issue"
added docs/internals-ja/report-an-issue.md
added docs/internals-ja/versions.md
added docs/guide-ja/intro-yii.md
Merge branch 'master' into docs-ja-2014-10-15b
Merge pull request #5581 from softark/docs-ja-2014-10-15b

[ci skip] Docs ja 2014 10 15b