go.talks/2012/chat: some minor cleanups
go.talks/2012/chat: some minor cleanups

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/8695050

bryanxu/go-zh.talks,webfd/go-zh.talks,d0f/go-zh.talks,bryanxu/go-zh.talks,d0f/go-zh.talks,d0f/go-zh.talks,bryanxu/go-zh.talks,webfd/go-zh.talks,bryanxu/go-zh.talks,webfd/go-zh.talks,webfd/go-zh.talks,d0f/go-zh.talks,d0f/go-zh.talks,d0f/go-zh.talks,webfd/go-zh.talks,bryanxu/go-zh.talks,webfd/go-zh.talks,bryanxu/go-zh.talks