Merge branch 'master' into t

* master:
  go/zodb/fs1: Fix access to whiteout
  go/zodb/fs1tools: tests: Use fresh dumper for each subtest
  go/zodb/fs1: Fix Python database generator to work with recent zodbtools
  go/zodb/zeo: msgpack.{Encode,Decode} -> msgpack.{Marshal,Unmarshal}
  go/neo/proto: UUID -> NID (NodeID)
  go/neo/internal/xsha1: New package to compute NEO-flavoured SHA1
  go/neo/t/tzodb.go: Switch to tasks and task-integrated logging
  go/internal/task: New package  (draft)
  go/internal/log: New package  (draft)
  go/internal/xcontext/task: New package  (draft)