(this should fix some buildbot test failures)

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.