Some extra (mostly tests?) modules included

[thatch]

From a spot-check, there are some extra modules that don't end up in site-packages on a standard install.

ctypes.test.test_cfuncs
distutils.tests.test_build_scripts
test.badsyntax_pep3120
test.test_asyncio.test_futures
test.test_subprocess
json.re (on 2.7)

Most of these aren't going to pose a big problem for me, but considering top-level names only test.* will. Would you accept a pull request that filters these (just test.* for now) in fetch?

[thatch]

On 3.9, there is a lib.libpython3 that is very problematic for usort's use of detecting stdlib top-level names. I fixed and re-ran fetch with some small changes, and it's excluding some others, like posixpath now. I think something has changed in the data upstream.

thatch@e387540 (and changes to fetch script in the couple of commits prior)

[thatch]

@CJ-Wright I saw your PR #39 -- looks like you didn't use stdlib_list.fetch for that?

[woodruffw]

Folding under #80.