Let `mio::Sender` implement the `Clone` trait
Let `mio::Sender` implement the `Clone` trait

asomers/mio,dwrensha/mio,carllerche/mio,fuchsia-mirror/third_party-mio,fuchsia-mirror/third_party-mio,mneumann/mio,murarth/mio,carllerche/mio,mneumann/mio,asomers/mio