Fix "manifest" error when building numpy 1.4.1 on Windows8 (64-bit) usin...

...g VSE2012

This commit prevents the following error from occurring:
error c1010070: Failed to load and parse the manifest. The system cannot find the file specified.

More details here: http://www.slicer.org/slicerWiki/index.php/Documentation/Labs/NUMPY171