Also switch "stating" to "statting" to describe applying os.Stat to
a resource; the former is more confusable than the latter.

Change-Id: I9d8e3506bd383f8f1479c05948c03b8c633dc4af
Reviewed-on: https://go-review.googlesource.com/42855Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>