Merge branch 'master' into t-fix-flaky-testload

* master:
  go/neo/neonet: Fix client handshake not to accept server encoding if it is different from what client indicated
  go/neo/neonet: Demonstrate problem in handshake with NEO/py
  go/neo/neonet: Dedicate an error type to indicate "protocol version mismatch" as handshake failure cause