Issue #12965: Clean up C-API docs for PyLong_AsLongLong(AndOverflow); clarify that __int__ will be called for non-PyLongs

Issue #12965: Clean up C-API docs for PyLong_AsLong(AndOverflow); clarify that __int__ will be called for non-PyLongs

mktime() when timezone offest is supplied.

Loosely based on the work by Hirokazu Yamamoto.

Patch by Hallvard B Furuseth.

use. Make the get_entity 'method' a module function as it did not use 'self'.
Delete buggy _find_constructor function that is not needed, at least in 3.x.
Revise get_argspec so all tests pass.  Add and fix NEWS entries.

Previously multiprocessing only expected int or str.  It also wrongly
used an exit code of 1 when the argument was a string instead of zero.

Initial patch by mouad

break someone's over specified test that depends on the exact error message.

when the path existed and had the S_ISGID mode bit set when it was not
explicitly asked for.  This is no longer an exception as mkdir cannot control
if the OS sets that bit for it or not.

'name' to 'expression' as the latter is what the string actually represents.
The bug in this issue was only catching NameError and AttributeError when
evaluating an expression that was not necessarily a name.

Code patch by Roger Serwy.

Initial patch by Michael Driscoll, I added the example.