add efficient filesystem handling for guard
Revert "add efficient filesystem handling for guard"

This reverts commit 6ba615c5866021a30d6b2c50ae33044b180dd14b.
Merge branch 'official'
Merge branch 'official'
Merge branch 'official'
翻译了部分文档，请进一步完善
Merge remote-tracking branch 'richard-ma/master' into translation/en
Merge pull request #328 from saberma/translation/en

英文版本翻译