If overlay encryption is required between peers, the fast datapath
forwarder returns an error rather than aborting the process, allowing
the overlay switch to fall back gracefully to an encrypted sleeve
overlay connection.
when encountering an unknown peer in received gossip, rather than
ignoring the entire gossip we create a placeholder Peer. This has
version 0 and uid 0, which means it will be replaced by any complete
peer information subsequently received via gossip.
The same piece of GossipData can be shared and subject to different
Merge operations. We either need to copy the data when we share it, or
create copies on modification, i.e. copy-on-write.
We choose the latter, since it is more efficient and there is just one
mutating operation.
Fixes#1697.
This is mostly a matter of moving some files, changing package names,
changing some imports, and changing some type references.
We duplicate the odd constant & global var, and the intmac/macint
functions, since neither 'router' or 'mesh' nor, really,' common' are
a natural home for them.
Adam Harrison