Patch by Martin Panter, reviewed by Serhiy Storchaka and R. David Murray.

Patch by Vinod Kurup.

Previous approach of installing coroutine wrapper in loop.set_debug() and
uninstalling it in loop.close() was very fragile.  Most of asyncio tests
do not call loop.close() at all.  Since coroutine wrapper is a global
setting, we have to make sure that it's only set when the loop is
running, and is automatically unset when it stops running.

Issue #24017.

Changes:

* Fixed a ResourceWarning warning
* Used argparse instead of getopt

if they called on a closed object.

Patch by John Hergenroeder.

Patch from Marc-Andre Lemburg.

METH_VARARGS methods on _sqlite.Connection.

anywhere in the name of the current directory.

Basically, s/thread/coroutine/.

assertWarnsRegex() checks are not longer successful if the callable is None.

Added tests for assertRaises().

during closing expatreader.  Fixed a regression introduced in issue #23865.