go.exp/locale: added String method for scriptID type.
go.exp/locale: added String method for scriptID type.

R=r
CC=golang-dev
https://golang.org/cl/8362043

go-src/inotify,AkihiroSuda/golang-exp-aspectgo,AkihiroSuda/golang-exp-aspectgo,JamesDunne/exp,golang/exp,golang/exp,JamesDunne/exp,AkihiroSuda/golang-exp-aspectgo,golang/exp