GitLab

network interface now allows setting Listeners after the fact.
This is useful to create the network and start listening as
separate steps. And to keep the network up to date on new
addresses the node might have to listen to.

This commit introduces a backoff when failing to dial
peers. It makes everything much faster.

cc @whyrusleeping

The net package is the next to move. It will be massaged
a bit still to fix the Network / "NetworkBackend" conflict.