Replace DL_IMPORT with PyMODINIT_FUNC and remove "/export:init..." link

command line for Windows builds.  This should allow MSVC to import and
build the Python MSVC6 project files without error.

Modules/mmapmodule.c

@@ -1051,7 +1051,7 @@ static struct PyMethodDef mmap_functions[] = {
 	{NULL,		NULL}	     /* Sentinel */
 };
 
-DL_EXPORT(void)
+PyMODINIT_FUNC
 	initmmap(void)
 {
 	PyObject *dict, *module;