issues in: 909005 and 17361001, as well as completely as possible issues
539444, 760475, 777588, 889153, 953599, 1025525, 1063924, and 658749.
This patch also includes doc and test updates as necessary.

Cleaned up the unit test.

 http://mail.python.org/pipermail/python-dev/2008-June/079988.html

Python 2.6 should stick with PyString_* in its codebase.  The PyBytes_* names
in the spirit of 3.0 are available via a #define only.  See the email thread.

Add a note about using the new AST module.

to ease standalone use of the algorithm.

more robust.

It would be great if someone could review both sematics, markup, and
spelling, and correct the versionadded and versionchanges markers.

PyDict_Get/SetItemString.

ctypes maintains thread-local storage that has space for two error
numbers: private copies of the system 'errno' value and, on Windows,
the system error code accessed by the GetLastError() and
SetLastError() api functions.

Foreign functions created with CDLL(..., use_errno=True), when called,
swap the system 'errno' value with the private copy just before the
actual function call, and swapped again immediately afterwards.  The
'use_errno' parameter defaults to False, in this case 'ctypes_errno'
is not touched.

On Windows, foreign functions created with CDLL(...,
use_last_error=True) or WinDLL(..., use_last_error=True) swap the
system LastError value with the ctypes private copy.

The values are also swapped immeditately before and after ctypes
callback functions are called, if the callbacks are constructed using
the new optional use_errno parameter set to True: CFUNCTYPE(...,
use_errno=TRUE) or WINFUNCTYPE(..., use_errno=True).

New ctypes functions are provided to access the ctypes private copies
from Python:

- ctypes.set_errno(value) and ctypes.set_last_error(value) store
  'value' in the private copy and returns the previous value.

- ctypes.get_errno() and ctypes.get_last_error() returns the current
  ctypes private copies value.

(I didn't regen configure, since I don't have a working autoconf.)