Patch by Roger Serwy.

to a single #define instead of having several copies in several files.

This excludes the Modules/ tree (datetime and expat both have a copy
for their own purposes with no need for it to be the same).

Patch by Erno Tukia.

Issue13726 - Fix the  ambiguous -S flag in regrtest. It is -o/--slow for printing the 10 slowest test.

Close *13753 'seq' now 'iterable'

Issue9637 - Explain in getproxies_environment that <scheme>_proxy environ variable case does not matter.

in comparison string that argparse does not add when program name is blank.

return False when the event was set and cleared right after.

On platforms that do not support (symbolic) links, tarfile offers a
work-around and extracts a link in an archive as the regular file the link is
pointing to. On other platforms, this code was accidentally executed even
after the link had been successfully extracted which failed due to the already
existing link.