reader/writer/conn: log levels and delegates
reader/conn: add requeue without backoff
reader: add HandlerFunc helper interface
message: drop EncodeBytes; s/Write/WriteTo; drop binary.{Read,Write}
reader: consistent connect method names
reader: drop SetMaxInFlight; un-export ConnectionMaxInFlight
reader: s/AddHandler/SetHandler and change semantics
reader: move around ReadUnpackedResponse
another logging pass
golint
s/EnableAsync/DisableAutoResponse
bump v0.4.0-alpha