* master:
  go/neo/neonet += Join
  go/neo/xtls: New package to build TLS configs for peer-to-peer internetworking
  go/zodb/zeo: Close networkers

The utility to create Networker suitable for interoperating with nodes
in a NEO cluster, be it TCP, TLS/TCP, TLS/lonet, etc. See added comments
for details.

See ConfigForP2P comment for details.

xnet.Networker added Close recently and is now required to be explicitly
closed by the user:

kirr/go123@01a77bb9