requirements: hgdistver
setup_entry_point()
setup: entry_points, get_version_from_scm
commands.tox: use path.py
load_zetup_config(), ZETUP_CONFIG_PACKAGE setting
scripts/zetup: create __init__.py and VERSION for ZETUP_CONFIG_PACKAGE
find_zetup_config()
zetuprc: packages, zetup_config_package