hgext/__init__.py

tests: add notes about broken `hg log --follow <file>` with copies in extras

I also removed some unnecessary `#if no-changeset` where the `#else`
was the same :P

Differential Revision: https://phab.mercurial-scm.org/D9204

from __future__ import absolute_import
import pkgutil

__path__ = pkgutil.extend_path(__path__, __name__)