json: encode \r and \n in strings as e.g. "\n", not "\u000A"
json: encode \r and \n in strings as e.g. "\n", not "\u000A"

This is allowed by the JSON spec and is shorter/easier to read.

R=golang-dev, bradfitz, rsc
CC=golang-dev
http://codereview.appspot.com/4678046

Committer: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang