Add line explaining the "%sort" test.
- Issue #18709: Fix CVE-2013-4238. The SSL module now handles NULL bytes
  inside subjectAltName correctly. Formerly the module has used OpenSSL's
  GENERAL_NAME_print() function to get the string represention of ASN.1
  strings for `rfc822Name` (email), `dNSName` (DNS) and
  `uniformResourceIdentifier` (URI).
null merge with 2.6
#18798: fix typo in test_fcntl.  Patch by Vajrasky Kok.
Issue #18757: Improved cross-references in the concurrent package.