os/exec: explicitly mention Cmd.Wait() has to be called eventually
os/exec: explicitly mention Cmd.Wait() has to be called eventually

LGTM=minux.ma, r
R=golang-codereviews, minux.ma, r
CC=golang-codereviews
https://codereview.appspot.com/67280043

Committer: Rob Pike <4dc7c9ec434ed06502767136789763ec11d2c4b7@golang.org>

pombredanne/go-deleteme,tv42/old-go,tv42/old-go,pombredanne/go-deleteme,pombredanne/go-deleteme,tv42/old-go,tv42/old-go,pombredanne/go-deleteme,tv42/old-go,tv42/old-go,pombredanne/go-deleteme,pombredanne/go-deleteme,tv42/old-go,pombredanne/go-deleteme