Issue #27778: Expose the Linux getrandom() syscall as a new os.getrandom()
function.

This change is part of the PEP 524.

Initial patch by Alex LordThorsen.

This completes PEP 519.

Issue #17884.

This is to add support for os.exec*() and os.spawn*() functions. Part
of PEP 519.

Patch by Brett Cannon.

C implementation of unpickler.  UnpicklingError is now raised instead of
AttributeError and ValueError in some cases.

glob module; they are now about 3--6 times faster.

Issue #27928: Add scrypt (password-based key derivation function) to hashlib module (requires OpenSSL 1.1.0).