doc: remove ExpressivenessOfGo.pdf         It has been moved to go.talks/2010/ExpressivenessOfGo-2010.pdf         URL: http://talks.golang.org/2010/ExpressivenessOfGo-2010.pdf
doc: remove ExpressivenessOfGo.pdf
        It has been moved to go.talks/2010/ExpressivenessOfGo-2010.pdf
        URL: http://talks.golang.org/2010/ExpressivenessOfGo-2010.pdf

R=r
CC=golang-dev
http://codereview.appspot.com/6660046

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