[Distutils] Patch for build_ext.py (Win32)

[Lyle Johnson]

> No, it's the job of the CCompiler classes to ensure that the files they
> are about to write can be written, ie. that os.path.dirname(output_file)
> exists before running the compile/link/whatever that attempts to create
> output_file.
>

Yes, the problem is that during the link (i.e. when we're actually making
the Windows DLL) it actually creates (well, tries to create) the following
*three* files:

	build\lib.win32\MyExtensionName.pyd
	build\temp.win32\Release\MyExtensionName.lib
	build\temp.win32\Release\MyExtensionName.exp

For the record, here's what my distutils-conjured link line looks like:

	link.exe /DLL /nologo /INCREMENTAL:NO /LIBPATH:../dtf \
		/LIBPATH:D:\Progra~1\Python\libs DTF.lib \
		build\temp.win32\Release\core_wrap.obj \
		/OUT:build\lib.win32\dtf\core.pyd /export:initcore \
		/IMPLIB:build\temp.win32\Release\dtf\core.lib

You are correct that link_shared_object() takes care of mkpath'ing the
output directory for the DLL itself but it does *not* create the needed
directories for the scratch files ("core.lib" and "core.exp"). So perhaps
the patch that I originally suggested for build_ext.py should be moved into
link_shared_object() instead. It doesn't matter to me as long as somebody
creates that directory before we try to dump files into it ;)

Lyle