backport context argument of urlopen (#22366) for pep 476

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branch : 3.4
extra : source : c0b0dda16009091a3c110b5f7c01762190ba835a
extra : amend_source : 86e8200837dfc94f2293767df8bc72d61a7b8f68
Issue #22770: Prevent some Tk segfaults on OS X when running gui tests.
When running tests in subprocesses with the regrtest -j option, a bug
in Cocoa Tk can result in a Tcl segfault.  Avoid the problem by forcing
Tk to fully initialize as an OS X gui process before destroying the
Tcl instance and creating another. (Original patch by Serhiy Storchaka)

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branch : 3.4
Issue #22770: merge from 3.4
Issue #17896: Move Windows external lib sources from .. to externals.

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branch : 3.4
Issue #17896: Move Windows external lib sources from .. to externals.

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rename : PCbuild/build_ssl.py => PCbuild/prepare_ssl.py
Fix test_urllib without the ssl module
#22751: fix test___all__ warning about modified environment in the tests.  Patch by Michael Cetrulo.

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branch : 3.4
#22751: merge with 3.4.
Issue #22388: Unified the style of "Contributed by" sentences in What's New.

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branch : 3.4
Issue #22388: Unified the style of "Contributed by" sentences in What's New.
Merge heads

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branch : 3.4
Merge heads
Null merge
Fix English phrasing.

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branch : 3.4
Reflow paragraph.

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branch : 3.4
Merge asyncio doc English phrasing fix.
Issue #22335: Fix crash when trying to enlarge a bytearray to 0x7fffffff bytes on a 32-bit platform.

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branch : 3.4
Issue #22335: Fix crash when trying to enlarge a bytearray to 0x7fffffff bytes on a 32-bit platform.
Merge heads
wrap

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branch : 3.4