Add build_py and sdist to bootstrap metadata. Ensures distutils versi…

…ons aren't used while bootstrapping egg-info.

bootstrap.egg-info/entry_points.txt

@@ -1,11 +1,15 @@
 [distutils.commands]
 egg_info = setuptools.command.egg_info:egg_info
+build_py = setuptools.command.build_py:build_py
+sdist = setuptools.command.sdist:sdist
 
 [distutils.setup_keywords]
 include_package_data = setuptools.dist:assert_bool
 install_requires = setuptools.dist:check_requirements
 extras_require = setuptools.dist:check_extras
 entry_points = setuptools.dist:check_entry_points
+exclude_package_data = setuptools.dist:check_package_data
+namespace_packages = setuptools.dist:check_nsp
 
 [egg_info.writers]
 PKG-INFO = setuptools.command.egg_info:write_pkg_info