Support of named attributes in jdk7

[Florian Weimer]

* Alan Bateman:

> One thing that isn't clear to me about ntfs-3g is the conversion
> to/from Unicode for both file names and extended attribute names when
> accessing NTFS. The extended attribute names in our API are provided
> by the application as Unicode strings and so are encoded to bytes for
> the *xattr calls.

Will there be a bypass to get to the bytes directly?  The
non-addressable names issue on non-Windows platforms is a bit
annoying.