Eliminate proto.Unmarshal from generated gRPC code.
Eliminate proto.Unmarshal from generated gRPC code.

Corresponds to https://github.com/grpc/grpc-go/pull/179.

trdata/protobuf,golang/protobuf,tamird/protobuf-2,skyportsystems/go-protobuf,ekle/protoc-gen-goweb_test,aoeu/protobuf,fuchsia-mirror/third_party-github.com-golang-protobuf,ekle/protoc-gen-goweb,jmptrader/protobuf-1,jeremyletang/protobuf,ArtemTeleshev/go-protobuf,jrbarron/protobuf,alskjstl/protobuf,kung-foo/protobuf,adnaan/protobuf,francoishill/protobuf,tamird/protobuf-2,trdata/protobuf,hailocab/protobuf,golang/protobuf,eduardiazf/protobuf,daemonl/protobuf,qinlodestar/protobuf,skyportsystems/go-protobuf,csuideal/protobuf,mwitkow-io/protobuf,fuchsia-mirror/third_party-github.com-golang-protobuf