changelog: fix the diverted opener to accept more kwargs
The current code prevent the use of `atomictemp` file with the changelog
opener. I do not see a good reason for this limitation.
Differential Revision: https://phab.mercurial-scm.org/D7831
# name space package to host third party extensions
from __future__ import absolute_import
import pkgutil
__path__ = pkgutil.extend_path(__path__, __name__)