bpo-33497: Add errors param to cgi.parse_multipart and make an encoding in FieldStorage use the given errors (GH-6804)

https://bugs.python.org/issue32769

Most of the parameters were added in 3.4.4 (b9bf913a), but this
change was not documented

Clarify that flush is implied when the call to write contains a newline character.

The urllib.robotparser's __str__ representation now includes wildcard
entries and the "Crawl-delay" and "Request-rate" fields. Also removes extra
newlines that were being appended to the end of the string.

This happens in the NixOS build sandbox, for example, where the only
other user is nobody with home directory /.

./.github/PULL_REQUEST_TEMPLATE.md:8: MD031 Fenced code blocks should be
surrounded by blank lines
./.github/PULL_REQUEST_TEMPLATE.md:10: MD031 Fenced code blocks should
be surrounded by blank lines
./.github/PULL_REQUEST_TEMPLATE.md:19: MD031 Fenced code blocks should
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./.github/PULL_REQUEST_TEMPLATE.md:21: MD031 Fenced code blocks should
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small_stmt -> compound_stmt

The hash implementation casts the input pointer to uint64_t* and directly reads
from this, which may cause unaligned accesses. Use memcpy() instead so this code
will not crash with SIGBUS on sparc.

https://bugs.gentoo.org/show_bug.cgi?id=636400

Pass os.environ's copy to new process created at test_posix:
test_specify_environment. Otherwise important variables such as
LD_LIBRARY_PATH are not set and the child process might not work at all
in an environment where such variables are required for Python to function.

This also fixes https://bugs.python.org/issue33420

random() takes precedence over getrandbits() if defined later
in the class tree.

* Expose the sigset_t converter via private API _Py_Sigset_Converter().
* Use Argument Clinic for parsing sigset_t in signalmodule.c.
* Raise ValueError instead OverflowError for integers out of
  the C long range.

Based on patch by Pablo Galindo Salgado.

bpo-33422: Fix quotation marks getting deleted when looking up byte/string literals on pydoc. (GH-6701)

Also update the list of string prefixes.

Currently, "pip3 install --upgrade pip" unconditionally installs a
"pip" alias even for Python 3.  If a user has an existing Python 3.x
installed from a python.org macOS installer and then subsequently
manually updates to a new version of pip, there may now be a stray
"pip" alias in the Python 3.x framework bin directory which can cause
confusion if the user has both a Python 2.7 and 3.x installed;
if the Python 3.x fw bin directory appears early on $PATH, "pip"
might invoke the pip3 for the Python 3.x rather than the pip for
Python 2.7.  To try to mitigate this, the macOS installer script
for the ensurepip option will unconditionally remove "pip" from
the 3.x framework bin directory being updated / installed.  (The
ambiguity can be avoided by using "pythonx.y -m pip".)