update: properly overwrite `check` config with `--no-` variants
Before this change `--merge` override `commands.update.check=abort/noconflict`,
and `--check` "override" `commands.update.check=none/linear`. However the
`--no-merge` and `--no-check` version where not doing anything.
The `--no-` two flags now behave properly.
Differential Revision: https://phab.mercurial-scm.org/D11851
# name space package to host third party extensions
from __future__ import absolute_import
import pkgutil
__path__ = pkgutil.extend_path(__path__, __name__)