Issue #26248, patch written by Ben Hoyt:

1) Clarify that the return values of is_dir()/is_file()/etc are cached
   separately for follow_symlinks True and False.
2) Be more specific about when the functions require a system call, and how it
   relates to caching and follow_symlinks.
3) DRY up common stuff between is_dir and is_file by saying "Caching, system
   calls made, and exceptions raised are as per is_dir" in is_file.
4) Tweak to the first paragraph of docs for is_dir/is_file to simplify: assume
   the follow_symlinks=True default, then note the follow_symlinks=False
   non-default case after.

invalid pattern.

Patch by Thomas Nyberg.

* Update description of the --system-site-packages option
* Show --copies option in the usage

Based on patch by Hagen Fürstenau and Daniel Urban.

Testing for a non-existing certificate file is already done in test_errors().
Copy wrongcert.pem from Python 2 and use it to test the behaviour with a
mismatched certificate.

non-atomic attributes.

of PyArg_Parse*() functions.

* Issue #25234: Skip test_eintr.test_open() under OS X to avoid hanging
* Issue #25868: Try to make test_eintr.test_sigwaitinfo() more reliable
  especially on slow buildbots. Use a pipe to synchronize the parent and the
  child processes.

Issue #26227: On Windows, getnameinfo(), gethostbyaddr() and gethostbyname_ex()
functions of the socket module now decode the hostname from the ANSI code page
rather than UTF-8.

Also add some more tests. Based on patch by Sye van der Veen.

Most of the docs has already been updated in c3c188a0325a.

Patch by Raphael Das Gupta.

Augment htest to include all major IOBinding functions.

Issue #26217: resize_compact() must set wstr_length to 0 after freeing the wstr
string. Otherwise, an assertion fails in _PyUnicode_CheckConsistency().

Issue #25907: Use {% trans %} tags in HTML templates to ease the translation of
the documentation. The tag comes from Jinja templating system, used by Sphinx.

Patch written by Julien Palard.

Issue #25843: When compiling code, don't merge constants if they are equal but
have a different types. For example, "f1, f2 = lambda: 1, lambda: 1.0" is now
correctly compiled to two different functions: f1() returns 1 (int) and f2()
returns 1.0 (int), even if 1 and 1.0 are equal.

Add a new _PyCode_ConstantKey() private function.

A single call to Pool.apply_async() will create only one process. To use all
of the pool's processes, it should be invoked multiple times:

    with Pool(processes=4) as pool:
        results = [pool.apply_async(func, ()) for i in range(4)]

Patch by Davin Potts.

PyMapping_Values in Include/abstract.h and Doc/c-api/mapping.rst.

Patch contributed by Sonali Gupta.

This change helps to ignore text of PSF, BEOPEN.com and CNRI licenses when
translating the documentation. Patch written by Julien Palard who is
translating Python 3.5 doc to french. Text of other licenses already used
preformatted format.