Merge branch 'master' into t

* master:
  go/*: Adapt to xnet.Networker changes wrt Listen and cancellation
  go/internal/xtesting: DrvTestWatch: Verify that watching works with empty transactions
  go/zeo: tests: Terminate spawned processses with SIGTERM instead of SIGKILL
  go/zodb/zeo: Factor-out verifying empty database into xtesting.DrvTestEmptyDB
  go/neo/t: .nxdtest: nxdtest changes summaryf signature to include stderr