`public TreePath(IntPtr raw) : base(raw) { }`

and

```
protected override void Free (IntPtr raw)
{
    gtk_tree_path_free (raw);
}

[Obsolete("Gtk.TreePath is now freed automatically")]
public void Free() {}
```

I'm not sure what it means about being freed automatically.  It seems like it's not TreeSelection.cs's responsibility to free this, it seems like TreePath.cs should be doing that.