doc/install-source.html: recent ARM and 386 updates
doc/install-source.html: recent ARM and 386 updates

R=golang-dev, dave, adg, remyoudompheng, r
CC=golang-dev
https://codereview.appspot.com/6845083

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