Use test.support and unittest features.  Fix duplicated test (bad merge in r79033).  Fix comment for issue #7902.

zipimport is now able to load a module with an unencodable filename.

Write a message formatted by PyUnicode_FromFormatV() to sys.stdout and
sys.stderr.

Some of these are genuine bugs with objects bigger than 2GB, but
my system doesn't allow me to write tests for it.

encoding and surrogateescape error handler. Patch written by David Watson.

Reindent also posix_getlogin(), and fix a typo in the NEWS file.

encoding and surrogateescape error handler. Patch written by David Watson.

using the filesystem encoding and surrogateescape error handler. Patch
written by David Watson.

Store builtins in cell variables to speed-up the common path,
reducing the chance of a lock needing to block at all.