To fix the build on some windows machines where exporting the changed INCLUDE paths messes things up.

Merged from revision 1409408 of https://svn.apache.org/repos/asf/incubator/ooo/branches/gbuild:
# HG changeset patch
# User Hans-Joachim Lankenau <hjs@openoffice.org>
# Date 1300125618 -3600
# Node ID b4abd2828ea57472570b5b6ed991baf114e0f48f
# Parent  f53b9337ae7a62b654cd60701660dfc7cf008aab