dlogger: Increase resilience to docker api failure
dlogger: Increase resilience to docker api failure

This commit adds some extra resiliency to the docker logger in the case
of API failure from the docker daemon, by restarting the stream from the
current point in time if the stream returns and the container is still
running.

dvusboy/nomad,burdandrei/nomad,burdandrei/nomad,burdandrei/nomad,hashicorp/nomad,hashicorp/nomad,hashicorp/nomad,burdandrei/nomad,hashicorp/nomad,dvusboy/nomad,dvusboy/nomad,hashicorp/nomad,burdandrei/nomad,burdandrei/nomad,dvusboy/nomad,dvusboy/nomad,dvusboy/nomad,burdandrei/nomad,hashicorp/nomad,dvusboy/nomad