R=golang-dev, r CC=golang-dev https://golang.org/cl/6544048
R=golang-dev, agl, r CC=golang-dev https://golang.org/cl/6530044
Package salsa20 implements the Salsa20 stream cipher as specified in http://cr.yp.to/snuffle/spec.pdf. (Reference implementation by dchest.) R=golang-dev, dchest CC=golang-dev https://golang.org/cl/6496083