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
# name space package to host third party extensions
from __future__ import absolute_import
import pkgutil
__path__ = pkgutil.extend_path(__path__, __name__)