localrepo: use revsymbol() in lookup()
lookup() seems to be about looking up a revision based on a symbol
that may come from the user (via the wire protocol), so revsymbol() is
appropriate here.
Differential Revision: https://phab.mercurial-scm.org/D3055
# name space package to host third party extensions
from __future__ import absolute_import
import pkgutil
__path__ = pkgutil.extend_path(__path__, __name__)