pathencode: improve error messages slightly
Both of these are conditions we should never hit, so we can afford to
be more verbose to make debugging less baffling.
Differential Revision: https://phab.mercurial-scm.org/D3589
# name space package to host third party extensions
from __future__ import absolute_import
import pkgutil
__path__ = pkgutil.extend_path(__path__, __name__)