Patch by Mark Mc Mahon.

Issue #9696: Fix exception incorrectly raised by xdrlib.Packer.pack_int when trying to pack a negative (in-range) integer.

Patch by Christoph Gohlke.
Closes #7639.

Issue #9343: Document that argparse parent parsers must be configured before their children. (Merge from 3.2.)

(so that stale test files, which can be very large, get wiped out)

Patch by Ben Hayden.

concurrent.futures.

concurrent.futures.

whole HTTP exchange, not only the opening.