to ensure that NTFS filesystems are mounted using ntfs-3g, which is
much better than the kernel NTFS driver. In particular, this
ensures that udisks will automount external NTFS drives with
read/write support. (See also
http://www.tuxera.com/community/ntfs-3g-faq/#plugandplay)
svn path=/nixpkgs/trunk/; revision=31055