updated to include subject

rename errors package to errs to avoid confusing with errors package.

no source pls in assert and die.

Better alert and die func

exposing internals of nats sub and nats pub

Readded the router for NATS.

Still a huge mess but pubsub seems good now, except the router part.

ops wrong env var

Renamed gocore to atrogolib

require user to provide start time when starting subscriber.