Patch by Serhiy Storchaka.

#16306: Fix multiple error messages when unknown command line parameters where passed to the interpreter.  Patch by Hieu Nguyen.

Patch by Serhiy Storchaka.

Issue #15379: Fix passing of non-BMP characters as integers for the charmap decoder (already working as unicode strings).
Patch by Serhiy Storchaka.

Remove versionadded from the tutorial, at a location where it produces more questions than it answers.

Also add tests for hashing.

Patch by Brian Brazil.

close subprocess.PIPE file descriptors when the child encounters an
error prior to exec.

used for stdin/stdout/stderr pipes to the child when fork() fails.

when not expected in subprocess.Popen.wait().

handled by Python to not persist after os.fork() in the child process.

Issue #16411: Fix a bug where zlib.decompressobj().flush() might try to access previously-freed memory.

Patch by Serhiy Storchaka.

Additionally, fix a bug where a MemoryError in allocating a bytes object could
leave the decompressor object in an invalid state (with its unconsumed_tail
member being NULL).

Patch by Serhiy Storchaka.