Using Mootools anf Hightchart

The default jQuery library is used. With this i can call Mootools instead.

```php
public function chart($chart,$engine)
    {
        return $chart->render($engine);
    }
```

```twig
{{ chart(chart,"mootools") }}
```

Don't forget to add the hightchart mootools adapteur.

*Don't find an other way exept modifiying render function.*