hgweb: handle "parity" internally in webutil.diffs()
There's apparently no reason to have the "parity" of diff blocks that
webutil.diffs() generates coming from outside the function. So have it
internally managed. We thus now pass a "web" object to webutil.diffs() to get
access to both "repo" and "stripecount" attribute.
# name space package to host third party extensions
from __future__ import absolute_import
import pkgutil
__path__ = pkgutil.extend_path(__path__, __name__)