gogo's varint reader buffers internally. If you use it then throw it away,
you'll drop data. This commit reverts to using msgio, but uses the varint
reader/writers instead.
* bring back plaintext 2.0.0 with new constructor
* fix deprecation comment
* rm unused context argument
* only check remote id validity if we actually have keys
* bring back msgio & simultaneous read/write
* add plaintext/2.0.0 (with ugly protoc hack)
* gofmt
* gofmt (for real this time)
* add `go_package` option to proto files
* Revert "add `go_package` option to proto files"
5a543a79bd
* less hacky protobuf imports
* add doc comment for PublicKeyFromProto
* clean up handshake
* go fmt, lol
* use network.MessageSizeMax for ggio reader