* y/py3: (32 commits)
  go/zodb: Fix _TestPersistentMapListLoad on py3_pickle3
  go/zodbpickle: Switch to unpickle with PyDict=y mode
  go/go.mode: v↑ github.com/kisielk/og-rek to pre-release with PyDict patches
  go/zodb/btree: go/zodb/fs1tools: Test it on all py2/py3 ZODB kinds of data we care about
  go/zodb/fs1: Remove old testdata files
  go/internal/xtesting: Switch to updated FileStorage testdata to validate LoadDBHistory
  go/zodbpickle: Switch to pickling with protocol=3
  go/zodb/zeo: Fix ZRPC/pickle binary and string encoding/decoding wrt py3
  go/zodb/zeo: Test it on all py2/py3 ZODB kinds of data we care about and wrt both ZEO/py2 and ZEO/py3
  go/zodb/demo: Test it on all py2/py3 ZODB kinds of data we care about
  go/zodb/zodbtools: Test it on all py2/py3 ZODB kinds of data we care about
  go/zodb/fs1tools: test: Normalize dumpOk from py3 to py2 syntax
  go/zodb/fs1tools: Test it on all py2/py3 ZODB kinds of data we care about
  go/zodb/fs1tools: DumperFsDump: Print size of every transaction record
  go/zodb/fs1tools: Regenerate testdata with ZODB 5.8.1
  go/zodb/fs1: Fix index save wrt py3
  go/zodb/fs1: Fix index load from py3 data
  go/zodb/fs1: Accept both FS21 and FS30 magics
  go/zodb/fs1: Test FileStorage on all py2/py3 ZODB kinds of data we care about
  go/zodb: Fix PyData.ClassName for py3_pickle3
  ...