Copy os.path stubs to posixpath

'posixpath' is used in Python std library modules.
Add minimal functools stubs
Include PSF 2 license for Python libs
Add unmodified CPython test.support module

From CPython 3.2.3.
Add unmodified CPython fnmatch module + tests
Add minimal gc stubs
Add minimal stubs for unicodedata
Add mininal platform module stubs
Add minimal sysconfig stubs
Add minimal locale stubs
Add minimal contextlib stubs
Add minimal stubs for importlib
Add minimal imp stubs
Add some logging.handlers stubs
test.support: Remove reference to multiprocessing
Add minimal doctest stubs
Add partial threading stubs
Add minimal _thread stubs
test.support: Remove code that uses ctypes
Add unittest.SkipTest to stubs