handling code in math.pow, in the hope of making all
tests pass on the alpha Tru64 buildbot.

The bits and pieces for the Windows side were already in place. The POSIX side is trivial (as usual) and uses os.kill().

More Windows related fixes are coming soon

Perform additional cleanup, mostly deleting from sys.modules, or clearing the warnings registry.

I finally got the time to update and merge Mark's and my trunk-math branch. The patch is collaborated work of Mark Dickinson and me. It was mostly done a few months ago. The patch fixes a lot of loose ends and edge cases related to operations with NaN, INF, very small values and complex math.

The patch also adds acosh, asinh, atanh, log1p and copysign to all platforms. Finally it fixes differences between platforms like different results or exceptions for edge cases. Have fun :)

Rewrite introductory section, and remove old section.  (It was already commented-out, but why keep it?)

e-mail address is for a previous employer.

Can we move the big long copyright statement into a sidebar or something?

undefined in ANSI C.

http://farmdev.com/thoughts/24/what-does-the-def-star-variable-or-def-asterisk-parameter-syntax-do-in-python-/

The right entry type to use isn't clear; operator seems wrong, because *,**,@
aren't being used in expressions here.  I put them as 'statement'; 'syntax'
might be better.

Issue 2439: add pkgutils.get_data() as a convenience wrapper for the PEP 302 get_data() API (contributed by Paul Moore)

Some other minor updates in _warnings.c:
- make a function static
- rename a shadowing local variable

better performance.