[Checkins] [zopefoundation/Zope] 15c1ed: Update to version 4.3

[Michael Howitz]

  Branch: refs/heads/master
  Home:   https://github.com/zopefoundation/Zope
  Commit: 15c1ed6c4bcca9cc895c7a54817fb2e5666cdecc
      https://github.com/zopefoundation/Zope/commit/15c1ed6c4bcca9cc895c7a54817fb2e5666cdecc
  Author: Michael Howitz <mh at gocept.com>
  Date:   2020-03-04 (Wed, 04 Mar 2020)

  Changed paths:
    M docs/INSTALL.rst

  Log Message:
  -----------
  Update to version 4.3