net/http: add parallel client/server benchmark R=bradfitz@golang.org
net/http: add parallel client/server benchmark
R=bradfitz@golang.org

R=bradfitz
CC=bradfitz, dave, dsymonds, gobot, golang-dev
http://codereview.appspot.com/6441134

apparentlymart/golang,gnanderson/go,tv42/old-go,dsriram/golang,apparentlymart/golang,apparentlymart/golang,apparentlymart/golang,pombredanne/go-deleteme,gnanderson/go,tv42/old-go,tv42/old-go,pombredanne/go-deleteme,gnanderson/go,dsriram/golang,gnanderson/go,gnanderson/go,apparentlymart/golang,pombredanne/go-deleteme,dsriram/golang,tv42/old-go,apparentlymart/golang,tv42/old-go,pombredanne/go-deleteme,pombredanne/go-deleteme,tv42/old-go,dsriram/golang,dsriram/golang,gnanderson/go,pombredanne/go-deleteme,pombredanne/go-deleteme,dsriram/golang,tv42/old-go,dsriram/golang,gnanderson/go,apparentlymart/golang