Issue #59

vet will flag %d on pointers, and ACME profiles come to x/crypto

The printf analyzer is getting stricter: an accepted proposal will make vet flag `fmt.Sprintf("%d", new(int))` and friends, on the reasonable grounds that printing a pointer's address in decimal is almost always a missing dereference rather than intent. Alongside it, x/crypto/acme picked up support for ACME profiles, tracking the in-progress IETF draft. On the reading pile, a writeup on pgx.CollectRows argues that ergonomic row-scanning APIs need not be slow, which pairs nicely with a short confession about making a Go reverse proxy 3.8x faster by fixing a single line.