private static void deletePath(File path) {
        if (path == null || ! path.exists()) return;

        try {
            if (path.isDirectory())
                IOUtils.recursiveDeleteDir(path);
            else
                Files.delete(path.toPath());
        } catch (IOException ioe) {
            log.log(Level.WARNING, "Failed deleting file/dir " + path);
        }
    }
When asking for a file reference, this handles RPC callbacks from config server with file data and metadata.
Uses the same Supervisor as the original caller that requests files, so communication uses the same
connection in both directions.

@author baldersheim
filedistribution/src/main/java/com/yahoo/vespa/filedistribution/FileReceiver.java