[Checkins] [zopefoundation/zope.app.locales] 01b137: Implement custom POT file header template (#11)

[Michael Howitz]

  Branch: refs/heads/master
  Home:   https://github.com/zopefoundation/zope.app.locales
  Commit: 01b137a8964c468a6f6f049112b21fe50136449c
      https://github.com/zopefoundation/zope.app.locales/commit/01b137a8964c468a6f6f049112b21fe50136449c
  Author: Michael Howitz <mh at gocept.com>
  Date:   2019-06-24 (Mon, 24 Jun 2019)

  Changed paths:
    M CHANGES.rst
    M src/zope/app/locales/extract.py
    A src/zope/app/locales/fixtures/header_template.txt
    M src/zope/app/locales/tests.py

  Log Message:
  -----------
  Implement custom POT file header template (#11)

Port usage of custom POT file header template here from `z3c.recipe.i18n`.
It is of general usage but untested and broken on Python 3 in z3c.recipe.i18n.