Change error message to indicate that VS2003 is necessary to build extension modules, not the .NET SDK.

SDK environment should be used. Fixes #1508010.

/F wrote the text docs, Englebert Gruber massaged it to latex and I
did some more massaging to try and improve the consistency and
fix some name mismatches between the declaration and text.

already verified in .frombuf() on the lines above.  If there was
a problem an exception is raised, so there was no way this condition
could have been true.

started after line 256.

rather than longs.  This also fixes the test for eval(-sys.maxint - 1).

The hppa ubuntu box sometimes hangs forever in these tests.  My guess
is that the wait is failing for some reason.  Use WNOHANG, so we won't
wait until the buildbot kills the test suite.

I haven't been able to reproduce the failure, so I'm not sure if
this will help or not.  Hopefully, this change will cause the test
to fail, rather than hang.  That will be better since we will get
the rest of the test results.  It may also help us debug the real problem.

*** The reason this originally failed was because there were many
zombie children outstanding before rev 47158 cleaned them up.
There are still hangs in test_subprocess that need to be addressed,
but that will take more work.  This should close some holes.

Also correct typo in Control.mapping.

specific encodings.

configure uses similar compiler flags as setup.py when doing the zlib test.

Without this patch configure would use the first shared library on the linker
path, with this patch it uses the first shared or static library on that path
just like setup.py.

foreign function argtypes sequence as long as they provide a
from_param method, no longer is it required that the object is a
ctypes type.

resulting Windows access violation will not be run by default.

returns a borrowed ref.  Many of the calls are open to attack.

Add a new function uses_seh() to the _ctypes extension module.  This
will return True if Windows Structured Exception handling (SEH) is
used when calling functions, False otherwise.

Fixes #1517388.

- change the pyexpat wrapper to not be so sensitive to this detail of the
  Expat implementation (the ex-crasher test still passes)

contains only the changes related to leaking the copy variable.