[Checkins] [zopefoundation/transaction] 05acc4: Transaction._free drops more references.

[Jason Madden]

  Branch: refs/heads/issue82
  Home:   https://github.com/zopefoundation/transaction
  Commit: 05acc4c1a6aaf343c6834589f74c9d7aa672aefa
      https://github.com/zopefoundation/transaction/commit/05acc4c1a6aaf343c6834589f74c9d7aa672aefa
  Author: Jason Madden <jamadden at gmail.com>
  Date:   2019-09-05 (Thu, 05 Sep 2019)

  Changed paths:
    M CHANGES.rst
    M docs/hooks.rst
    M transaction/_transaction.py
    M transaction/tests/test__transaction.py

  Log Message:
  -----------
  Transaction._free drops more references.

Specifically, synchronizers and its manager.

And abort() always invokes _free() even in the case of exceptions. commit() still doesn't so that the synchronizers are available for the expected abort().

Fixes #82