The attached patch updates the MSI build process to
build a mingw-compatible libpythonXX.a and install it
in the Python "libs" directory.

The additional step requires 2 executables, nm and
dlltool, to be available on PATH. These are part of the
binutils package of either mingw or cygwin. The build
should warn, and skip the inclusion of libpythonXX.a,
if the tools are not available.

Note: I do not have a Python build environment (no
Visual Studio .NET) and so cannot test this patch fully
- the msi.py script depends on VS.NET registry keys
that aren't available on my PC. I've checked that
libpythonXX.a is built correctly, but I can't ensure
that the MSI file gets built properly :-( Assistance in
testing this would be appreciated...