update godoc version for go tip

refs #68
move package sources from src/pkg to src

see: https://code.google.com/p/go/source/detail?r=f679ea289412c8c85a8ec9cb6582a1f82debce88

refs #68
remove pkg

refs #68
Merge pull request #69 from t-yuki/master

cmd/go: update doc.go to tip
fix translate. refs #69