go.tools/playground/socket: move package from go.talks
go.tools/playground/socket: move package from go.talks

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/13244049

maddyonline/tools,sshetty10/tools,josharian/tools,matryer/tools,matryer/tools,golang/tools,nicot/tools,josharian/tools,jdhenke/tools,josharian/tools,golang/tools,magiccao/tools,magiccao/tools,jdhenke/tools,cw2018/tools,argandas/tools,argandas/tools,magiccao/tools,4ad/tools,dmitris/tools,syreclabs/go-tools,runcom/tools,cw2018/tools,glasser/golang-tools,runcom/tools,nicot/tools,dmitris/tools,springning/tools,syreclabs/go-tools,syreclabs/go-tools,syreclabs/go-tools,golang/tools,sshetty10/tools,nicot/tools,cmars/tools,sshetty10/tools,runcom/tools,golang/tools,cw2018/tools,glasser/golang-tools,cmars/tools,golang/tools,argandas/tools,runcom/tools,springning/tools,magiccao/tools,maddyonline/tools,dmitris/tools,matryer/tools,nicot/tools,maddyonline/tools,cmars/tools,springning/tools,4ad/tools,syreclabs/go-tools,matryer/tools,cw2018/tools,jdhenke/tools,dmitris/tools,cmars/tools,jdhenke/tools,glasser/golang-tools,sshetty10/tools,josharian/tools,maddyonline/tools,syreclabs/go-tools,glasser/golang-tools,argandas/tools,4ad/tools,springning/tools