pprint: Add static types to test cases
Add TestCase.skipTest to unittest stubs
Adapt genericpath test cases to static typing

Also fix a few instances of what seem like bugs in the original code.
Add unittest.skip to stubs
Fix os.path.sameopenfile signature
Allow iterables as *args

Fixes some cases of #238.
Allow negative tuple indices

Fix #258.
posixpath: Fix function signature
posixpath: Adapt test cases to static typing
tempfile: Adapt test cases to static typing
Update unittest stubs
Fixes to set stubs
Add failing skipped test case
Add __code__ function attribute to stubs
Uncomment Unix-only functions in signal stubs
Add resource.error to stubs
subprocess: Update type annotations
subprocess: Adapt test cases to static typing
Clean up import
Clean up import