netrc file format doesn't support quotes and escapes.

See https://linux.die.net/man/5/netrc
(cherry picked from commit b24cd055)

(cherry picked from commit ac03c03b)

(cherry picked from commit 0d2c645d)

(cherry picked from commit 4f469c09)

Skip a test for unget_wch()/get_wch() on OpenBSD since they are broken
in ncurses 5.7.
(cherry picked from commit 7e68790f)

(cherry picked from commit 894ebd06)

bpo-31910: test_create_connection() now catchs also EADDRNOTAVAIL to
fix the test on Travis CI.
(cherry picked from commit 280c22a8)

Replace occurence of nested comments in blake2 reference implementation
with preprocessor directive for disabling unused code.

`blake2s-load-xop.h` is conditionally pulled in only on chips with XOP
support, among others the AMD Bulldozer. The malformed comments in the
source file breaks the build of `hashlib`'s `_blake2` on GCC 6.3.0.

Official reference code on github uses `GH-if` so this change should be
uncontroversial.
(cherry picked from commit 388cd85e)

Modify the code to use ncurses is_pad() instead of checking WINDOW
_flags field.  If your platform does not provide the is_pad(), the
existing way that checks the field will be enabled.

Note: This change does not drop support for platforms where do not
have both WINDOW _flags field and is_pad().
(cherry picked from commit 8bc7d635)

* Fix a compilation error on FreeBSD.
* Fix the data attribute size on Mac OS X.
(cherry picked from commit 2298fad5)

Document the following functions:

* PyObject_Malloc()
* PyObject_Calloc()
* PyObject_Realloc()
* PyObject_Free()

Fix also PyMem_RawFree() documentation.
(cherry picked from commit ec2cbdd1)

bpo-31897: Convert unexpected errors when read bogus binary plists into InvalidFileException. (GH-4171) (#4192)

(cherry picked from commit db91e0fe)

Removed a code that incorrectly detected in-place resizing in realloc()
 and wrote to freed memory.
(cherry picked from commit b484d560)

* Fixed the layout of the kqueue_event structure on OpenBSD and NetBSD.
* Fixed the comparison of the kqueue_event objects.
(cherry picked from commit b9052a0f)

(cherry picked from commit baac01e6)

test_curses now saves/restores signals. On FreeBSD, the curses module
sets handlers of some signals, but don't restore old handlers when
the module is deinitialized.

(cherry picked from commit 19f68301)

Update the kwarg in the documentation of `multiprocessing.pool.Pool.starmap_async`, from `error_back` to `error_callback` to match the source code.
(cherry picked from commit 11225753)

separators that are not bytes-like objects..
(cherry picked from commit a2314283)

(cherry picked from commit 006617ff)

(cherry picked from commit 5a4bbcd4)

Editor and output windows only see an empty last prompt line.
This simplifies the code and fixes a minor bug when newline is inserted.
Sys.ps1, if present, is read on Shell start-up, but is not set or changed.
(cherry picked from commit e86172d6)

Changes persist while IDLE remains open
(cherry picked from commit ed6554c4)

(cherry picked from commit 7351f9e5)

(cherry picked from commit d609b0c2)

(cherry picked from commit 56d1f5ca)

BytesWarning no longer emitted when the fromlist argument of
__import__() or the __all__ attribute of the module contain bytes
instances..
(cherry picked from commit 41c56940)

(cherry picked from commit 275d2d9c)

(cherry picked from commit 66caacf2)

test_unparse.DirectoryTestCase now stores the names sample to always
test the same files. It prevents false alarms when hunting reference
leaks.
(cherry picked from commit 8e482bea)

SyntaxError now is raised instead of SyntaxWarning.
(cherry picked from commit 3b66ebe7)

(cherry picked from commit 62adc55a)

bpo-31752: Fix possible crash in timedelta constructor called with custom integers. (GH-3947) (#4086)

Bad remainder in divmod() in intermediate calculations caused an assertion failure.
(cherry picked from commit 4ffd4653)

(cherry picked from commit 85f64302)

(cherry picked from commit 04e36af9)

(cherry picked from commit bcbdd2f8)

[3.6] bpo-28326: Fix multiprocessing.Process when stdout and/or stderr is closed or None. (GH-4073).  (#4075)

* bpo-28326: Fix multiprocessing.Process when stdout and/or stderr is closed or None. (#4073)

(cherry picked from commit daeefd2e)

* [3.6] bpo-28326: Fix multiprocessing.Process when stdout and/or stderr is closed or None. (GH-4073).
(cherry picked from commit daeefd2e)

and in codecs.escape_decode() when decode an escaped non-ascii byte.
(cherry picked from commit 56cb465c)