go.blog: fold the profiling Go article also fixed a few remaining references to `gopprof`.
go.blog: fold the profiling Go article
also fixed a few remaining references to `gopprof`.

R=golang-dev, r, adg
CC=golang-dev
https://codereview.appspot.com/9784046

webfd/go-zh.blog,webfd/go-zh.blog,d0f/go-zh.blog,bryanxu/go-zh.blog,bryanxu/go-zh.blog,d0f/go-zh.blog