Clarify section on tokens. Fixes issue 457.
Clarify section on tokens.
Fixes issue 457.

R=r
CC=golang-dev
http://codereview.appspot.com/181083

apparentlymart/golang,pombredanne/go-deleteme,tv42/old-go,h8liu/golang,pombredanne/go-deleteme,h8liu/golang,apparentlymart/golang,dsriram/golang,tianon/debian-golang,tianon/debian-golang,tianon/debian-golang,tianon/debian-golang,bdwalton/debian-golang,nightlyone/golang,h8liu/golang,apparentlymart/golang,pombredanne/go-deleteme,tianon/debian-golang,nightlyone/golang,ssrl/go,gnanderson/go,tv42/old-go,gnanderson/go,ssrl/go,apparentlymart/golang,apparentlymart/golang,ssrl/go,pombredanne/go-deleteme,tianon/debian-golang,nightlyone/golang,tianon/debian-golang,dsriram/golang,ssrl/go,gnanderson/go,nightlyone/golang,bdwalton/debian-golang,bdwalton/debian-golang,bdwalton/debian-golang,ssrl/go,apparentlymart/golang,h8liu/golang,tianon/debian-golang,dsriram/golang,tv42/old-go,tv42/old-go,pombredanne/go-deleteme,h8liu/golang,gnanderson/go,dsriram/golang,bdwalton/debian-golang,bdwalton/debian-golang,dsriram/golang,bdwalton/debian-golang,nightlyone/golang,tv42/old-go,ssrl/go,h8liu/golang,tv42/old-go,apparentlymart/golang,gnanderson/go,nightlyone/golang,ssrl/go,h8liu/golang,gnanderson/go,nightlyone/golang,dsriram/golang,pombredanne/go-deleteme,gnanderson/go,tv42/old-go,bdwalton/debian-golang,dsriram/golang,pombredanne/go-deleteme