to format short Python version.

not str.format call.

This was done so as to move users to `python3 -m venv` which prevents
confusion over which Python interpreter will be used in the virtual
environment when more than one is installed.

with specified exception type.  Original patch by Ramchandra Apte.

instead of deperecated cgi.escape().  Original patch by Raymond Hettinger.

pydoc.gui was removed over 3 years ago (#10818), this script has been
utterly bereft of worth since then.

Patch by Zachary Ware.

The user-facing scripts in PCbuild have been updated to be easier to use
and the buildbot scripts in Tools\buildbot have been updated to use the
user-facing scripts in PCbuild wherever possible.

Patch by David Bolen.

when building in a separate object tree. More people should build this way.
This may still fail if the source is unwritable, I haven't tested that yet.

It includes required changes in Makefile.pre.in and configure.ac
among other files.

Patch by Arfrever Frehtes Taifersar Arahesis.

requires them.  Disable executable bits and shebang lines in test and
benchmark files in order to prevent using a random system python, and in
source files of modules which don't provide command line interface.  Fixed
shebang line to use python3 executable in the unittestgui script.

The application object must return an iterable yielding bytestrings.

* The first line of Python script could be executed twice when the source
encoding (not equal to 'utf-8') was specified on the second line.

* Now the source encoding declaration on the second line isn't effective if
the first line contains anything except a comment.

* As a consequence, 'python -x' works now again with files with the source
encoding declarations specified on the second file, and can be used again
to make Python batch files on Windows.

* The tokenize module now ignore the source encoding declaration on the second
line if the first line contains anything except a comment.

* IDLE now ignores the source encoding declaration on the second line if the
first line contains anything except a comment.

* 2to3 and the findnocoding.py script now ignore the source encoding
declaration on the second line if the first line contains anything except
a comment.

Patch by Donald Stufft and Nick Coghlan

now detect Python source code encoding only in comment lines.

- document abitype.py, analyze_dxp.py, get-remote-certificate.py,
  import_diagnostics.py, parse_html5_entities.py.
- remove redemo.py which was moved to Tools/Demo.
- sort list into alphabetical order

Patch by Seydou Dia.