This adds C versions of methods used by ABCMeta that
improve performance of various ABC operations.

Also, use PYTHON_FOR_REGEN for clinic and blake2s_impl.c rather than PYTHON_FOR_BUILD, and update .travis.yml to make use of the change.

Adapt documentation for `copyright` and `credits` to reality.  Previously, the documentation implied that all each of `copyright`,
`credits`, and `license`, would print a message to call the object in order to see the full text.  In reality, only `license` exhibits this
behaviour, and `copyright` and `credit` print their full text either when printed, displayed, or called.

There was an extra dash in the example for re.sub().

A closing parentheses was missing.
Signed-off-by: Ngie Cooper <yaneurabeya@gmail.com>

Remove pkg_add -r python from FreeBSD installation section.
Moved to OpenBSD.

This note incorrectly stated that "Base64 has an expansion factor of 6
to 4" (it is actually 4 to 3). It was decided to remove the note.

Using the system and place-dependent default encoding for open()
is a bad idea for IDLE's system and location-independent files.

GUI test test_file_buttons() only looks at initial ascii-only lines,
but failed on systems where open() defaults to 'ascii' because
readline() internally reads and decodes far enough ahead to encounter
a non-ascii character in CREDITS.txt.

The PrintNameOffset field of the reparse data buffer
was treated as a number of characters instead of bytes.

Describe *text* as an alias for *universal_newlines* in more places that people are likely to be referred to.

This is not the ideal solution; this means that a test module is now
always included in the main python3x.dll.  However, we're already
including xxsubtype, so why not?

The new link is given in a red box on the old page.

We don't use debugger on Travis.

Importing unicodedata in sre_parse leads to failure in compilation.
unicodedata is unused during compilation, and is not compiled when this
file is imported. The error occurs when generating posix variables,
pprint is required. The dependency chain goes on like this:

sysconfig -> pprint -> re -> sre_compile -> sre_parse (this file)

This commits fixes compilation issues introduced by
2272cec13b53c405d86c45d404f035f201c0baef.
(Issue 30688, GH-5588)

Co-authored-by: Jonathan Eunice <jonathan.eunice@gmail.com>

Co-authored-by: Jake Davis <jcdavis@awedge.net>