executors for @ListenerSupport

[fommil]

by example...

    private final Executor executor = ...

    protected void fireReceivePacket(final Packet arg0) {
        for (final EmotivListener l : $registeredEmotivListener) {
            Runnable runnable = new Runnable(){
                @Override
                public void run() {
                    l.receivePacket(arg0);
                }
            };
            executor.execute(runnable);
        }
    }