fix windows stat issue

git-svn-id: http://libtorrent.googlecode.com/svn@9897 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda
merged stats fix from RC_0_16

git-svn-id: http://libtorrent.googlecode.com/svn@9898 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda