go.crypto/ssh: Update Dial to perform remote resolution of DNS names.
go.crypto/ssh: Update Dial to perform remote resolution of DNS names.

R=agl
CC=golang-dev
https://golang.org/cl/13010047

thomaso-mirodin/crypto,Carrotman42/crypto,progrium/crypto,conseweb/golangcrypto,guaiguaihw/crypto,progrium/crypto,golang/crypto,conseweb/golangcrypto,pki-io/crypto,mattharden/crypto,lucevers/crypto,cmars/tools,golang/crypto,ScriptRock/crypto,lucevers/crypto,Carrotman42/crypto,cmars/tools,juniorz/crypto,thomaso-mirodin/crypto,wooutl/golangcrypto,wooutl/golangcrypto,tca/crypto,mattharden/crypto,bford/golang-x-crypto,cheffo/crypto,ScriptRock/crypto,juniorz/crypto,guaiguaihw/crypto,kim-racktop/crypto,tca/crypto,bford/golang-x-crypto,zj8487/crypto,pki-io/crypto,zj8487/crypto,a-palchikov/crypto,cmars/tools,CodyGuo/crypto,kim-racktop/crypto,golang/crypto,a-palchikov/crypto,cheffo/crypto,cmars/tools,CodyGuo/crypto