Merge branch 'master' into t

* master:
  go/neo/neonet: Increase signal/noise in dump of packets with decode problems
  fixup! go/neo/proto: Switch enum encoding from int32 to int8
  go/zodb/zeo: Load: loadBefore RPC can return None to indicate non-existing object
  go/internal/xtesting: DrvTestLoad: Verify load of non-existing and not-yet-created objects