Based on patch by Martin Panter.

I would just outright delete them, but the readme in PCbuild recommended
their use, so I figure it would be nice to leave them there for a while.

It now recommends PCbuild/get_externals.bat instead of the scripts in
Tools/buildbot.

Patch by Jaivish Kothari.

and set comparisions.  Patch by Gareth Rees.

This is mostly a backport of issue #21907, but also includes a few
extras necessary to make the bulidbot scripts as thin as possible.

does support IPv6 and IPv4; www.python.org currently does not.

Backported issues #19619: encode() and decode() methods and constructors
of str, unicode and bytearray classes now emit deprecation warning for known
non-text encodings when Python is ran with the -3 option.

Backported issues #20404: io.TextIOWrapper (and hence io.open()) now uses the
internal codec marking system added to emit deprecation warning for known non-text
encodings at stream construction time when Python is ran with the -3 option.

24-bit samples are not supported in 2.7.

PyObject_IsInstance(), PyObject_RichCompareBool() and _PyDict_Contains()
to check for and handle errors correctly.

Original patch by David Moore.

value in the host header was set to "None".  Patch by Demian Brecht.