Also, update docs on how to re-generate.
Switches to using go4.org/grpc and go4.org/grpc-codegen/protoc-gen-go4grpc
for now.
Updates golang/go#19866
Updates golang/go#20222
Change-Id: Ifa8a123fca2a30f17270c3c558b7395a02064eae
Reviewed-on: https://go-review.googlesource.com/43560
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Add $GOPATH/src to the --proto_path so we can import the google
Timestamp definition instead of redefining a copy in our tree.
Change-Id: I09c3554fb025a32c9db4892b702ee2bedb3c0e53
Reviewed-on: https://go-review.googlesource.com/36899
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>