Issue #13988: cElementTree is deprecated and the _elementtree accelerator is automatically used whenever available.

directory tree instead of overwriting the input files.  Adds three command
line options: -o/--output-dir, -W/--write-unchanged-files and --add-suffix.

directory tree instead of overwriting the input files.  Adds three command
line options: -o/--output-dir, -W/--write-unchanged-files and --add-suffix.

Feature backports into stable release branches for 2to3 are allowed by
a special exemption:
 http://mail.python.org/pipermail/python-dev/2011-December/115089.html

Closes #9750

Closes #9750

Issue #10287: nntplib now queries the server's CAPABILITIES again after authenticating (since the result may change, according to RFC 4643).
Patch by Hynek Schlawack.

Issue #10287: nntplib now queries the server's CAPABILITIES again after authenticating (since the result may change, according to RFC 4643).
Patch by Hynek Schlawack.

The code used to call os.path.join to build a regex but without escaping
the backslash, which lead to test failures on Windows.  Antoine Pitrou
fixed it in 0a94e2f807c7 by enhancing the code to accept both / and \,
with proper escaping, but in my opinion this goes against the distutils
feature freeze, hence this change.

If I grepped correctly, this was the last outdated place.

Also, give a more helpful error message when opened with an invalid mode string.