Fix a ResourceWarning(unclosed socket). Patch written by Nadeem Vawda.

Fix a ResourceWarning(unclosed socket) if an exception is raised in the
constructor after the creation of the socket. Patch written by Nadeem Vawda.

- removed unnecessary struct_time to tuple conversion
- added more unit tests
(See issue #10827 for discussion.)

socket is now always non-blocking, regardless of the operating system.

Patch by Jean-Paul Calderone and Sandro Tosi.

Popen.communicate() avoids deadlocks and close the pipes when done. This commit
fixes a ResourceWarning(unclosed pipe).

Fix a ResourceWarning(unclosed file).

PyUnicode_FromFormat() and PyErr_Format() allocates a buffer of the needed
size, it is no more a fixed-buffer of 500 bytes.

There's still a bug here (the encode call shouldn't use the 'errors'
paramter), but I'll fix that later.

Instead of _testcapi.format_unicode() because it has a limited API: it requires
exactly one argument of type unicode.

will fix intermittent failures on some buildbots (issue #8458).

deletes its _block attribute, deal with that.  This prevents an uncaught
exception in a thread during test_thread.

This refactors a bit to better match what I did in the r87727 backport to 2.7.

and ctime functions.  The year range for time.asctime is now 1900
through maxint.  The range for time.ctime is the same as for
time.localtime.  The string produced by these functions is longer than
24 characters when year is greater than 9999.

Return msgbug on error is enough.

Don't need to handle unknown destructor anymore.

raising a ValueError, to fix repr().