talks: add 2016/refactor.article, based on my GothamGo talk

Change-Id: I62653a352773429c4517355d6c280289badd213f
Reviewed-on: https://go-review.googlesource.com/33723
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
20 files changed