New VFS module for implementing NTFS streams support on Mac OS X.

New VFS module for implementing NTFS streams support on Mac OS X.

This is a VFS module that implements NTFS streams support on HFS-like
filesystems, using the resource fork, the Finder info attribute and
Darwin extended attributes to store the stream data.

There are some  associated changes in core Samba code:

    1. fcntl cannot be supported for streams that are faked on top of extended
    attributes. In this case, we alter the locking layer to silently ignore
    ENOTSUP errors from the VFS.

    2. The VFS open call can fail if we detect a conflicting share mode (from
    either SMB or AFP). In this case we do the deferred open dance. This change
    needs to be resolved against other mechanisms for doing system-wide open
    modes.