From Robert Collins.

cleanup overflowing handling in unicode_decode_call_errorhandler and unicode_encode_ucs1 (closes #22518)

limited by 100.

Patch by Claudiu Popa.

I accidentally merged this in 90b07d422bd9; this merge addresses the
last review comments on the patch.

I accidentally committed this in 6375bf34fff6; this changeset addresses the
last review comments on the patch.

This is a perennial question and something someone opens a ticket for probably
every other month or so, so I'm surprised we didn't already have a FAQ entry
for it.

The original patch was written by M. Votz, refined first by Ezio Melotti and
further refined by me.

This patch brings the pure-python datetime more in-line with the C
module.  Patch contributed by Brian Kearns, a PyPy developer.  PyPy
project has been running these modifications in PyPy2 stdlib.

This commit includes:

- General PEP8/cleanups;
- Better testing of argument types passed to constructors;
- Removal of duplicate operations;
- Optimization of timedelta creation;
- Caching the result of __hash__ like the C accelerator;
- Enhancements/bug fixes in tests.

Patch by Yongzhi Pan.

Pointed out by Arfrever.

Pointed out by Arfrever.

Corresponding functions now accept `const char *` (issue #1772673).

Patch by Ian Cordasco, approved by Éric Araujo.

Patch by Jonathan Hosmer.

Original patch (and the idea of using _structure) by Abhilash Raj.

Patch by Jonathan Hosmer.

Note that the email version string in 3.3 and 3.4 is inaccurate, since it
still exists but wasn't updated while the code was.

Oleg Oshmyan.

Oleg Oshmyan.