Extract cross-platform condition variable support into a separate file and
provide user-mode non-recursive locks for Windows.

Prevent test_inspect from keeping alive a ton of frames and local variables by way of a global variable keeping a reference to a traceback.
Should fix some buildbot failures.

Issue #14657: The frozen instance of importlib used for bootstrap is now also the module imported as importlib._bootstrap.

Issue #14814: Add first draft of PEP 3144 ipaddress module documentation (initial patch by Sandro Tosi)

Improve an internal ipaddress test, add a comment explaining why treating networks as containers of interfaces rather than addresses would prove confusing

Patch by Serhiy Storchaka.

Patch by Serhiy Storchaka.

2) _mpd_qpow_mpd(): Abort the loop for all specials, not only infinity.

3) _mpd_qpow_mpd(): Make the function more general and distinguish between
   zero clamping and folding down the exponent. The latter case is currently
   handled by setting context->clamp to 0 before calling the function.

4) _mpd_qpow_int(): Add one to the work precision in case of a negative
   exponent. This is to get the same relative error (0.1 * 10**-prec)
   for both positive and negative exponents. The previous relative
   error for negative exponents was (0.2 * 10**-prec).

   Both errors are _before_ the final rounding to the context precision.

And don't use assert() anymore if check_maxchar is set: return -1 on error
instead.