config: add defaultvalue template keyword This patch tries to fix one of the issues mentioned in issue6014. This adds a new `defaultvalue` template keyword to be used with `hg showconfig` to get the default value of the config item. Differential Revision: https://phab.mercurial-scm.org/D6704

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