keepalive: headers are native strings, mark them as such
# skip-blame just marking some native strings
Differential Revision: https://phab.mercurial-scm.org/D2311
py3: use range instead of xrange on py3 in tests/test-ui-verbosity.py
xrange is not present on Python 3.
Differential Revision: https://phab.mercurial-scm.org/D2332