hgext3rd/__init__.py

cleanup: fix some latent open(path).read() et al calls we previously missed

This pattern was banned by check-code way back in 1b4b82063ce2 (may of
2011), but due to a regular expression rewriting bug in check-code
these particular callsites were never detected. Python 3.7 caught the
bug, which then exposed these errors.

Differential Revision: https://phab.mercurial-scm.org/D2863

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