See PEP 539 for details.

Highlights of changes:

- Add Thread Specific Storage (TSS) API
- Document the Thread Local Storage (TLS) API as deprecated
- Update code that used TLS API to use TSS API

* group the (stateful) runtime globals into various topical structs
* consolidate the topical structs under a single top-level _PyRuntimeState struct
* add a check-c-globals.py script that helps identify runtime globals

Other globals are excluded (see globals.txt and check-c-globals.py).

Windows buildbots started failing due to include-related errors.

* group the (stateful) runtime globals into various topical structs
* consolidate the topical structs under a single top-level _PyRuntimeState struct
* add a check-c-globals.py script that helps identify runtime globals

Other globals are excluded (see globals.txt and check-c-globals.py).

* bpo-30832: Remove own implementation for thread-local storage

CPython has provided the own implementation for thread-local storage
(TLS) on Python/thread.c, it's used in the case which a platform has
not supplied native TLS.  However, currently all supported platforms
(NT and pthreads) have provided native TLS and defined the
Py_HAVE_NATIVE_TLS macro with unconditional in any case.

* bpo-30832: replace NT with Windows

* bpo-30832: change to directive chain

* bpo-30832: remove comemnt which making no sense

* Doc nits for bpo-16500

* Fix more references

Python/thread_foobar.h is the template code that is threading adaptation
for new platforms, also hasn't been used on actual platforms.
Python/thread_*.h give concrete examples of adaptation instead of the
template code.

* bpo-6532: Make the thread id an unsigned integer.

From C API side the type of results of PyThread_start_new_thread() and
PyThread_get_thread_ident(), the id parameter of
PyThreadState_SetAsyncExc(), and the thread_id field of PyThreadState
changed from "long" to "unsigned long".

* Restore a check in thread_get_ident().