* Fix seek() method of codecs.open(), don't write the BOM twice after seek(0)
 * Fix reset() method of codecs, UTF-16, UTF-32 and StreamWriter classes
 * test_codecs: use "w+" mode instead of "wt+". "t" mode is not supported by
   Solaris or Windows, but does it really exist? I found it the in the issue.

after seek(0)

than strict

embedders of the interpreter to set sys.argv without also modifying
sys.path.  This helps fix `CVE-2008-5983
<http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-5983>`_.

(e.g. from .os import sep) and it failed, import would still try the implicit
relative import semantics of an absolute import (from os import sep). That's
not right, so when level is negative, only do explicit relative import
semantics.

Fixes issue #7902. Thanks to Meador Inge for the patch.

Forward port some code from Python3:

 * join surrogate pairs if sizeof(Py_UNICODE)==2
 * Enable non-BMP test on narrow builds using u"\U0001D121" instead of
   unichr(0x1D121)

Fix issue #8573 (asyncore._strerror bug): fixed os.strerror typo; included NameError in the tuple of expected exception; added test case for asyncore._strerror.

it from another thread.  Patch by Daniel Stutzbach.

When the error queue is not emptied, strange things can happen on the next SSL call, depending on the OpenSSL version.