Added parameter to setRendered(). Now rendered could already set to false and prototypes could be rendered multiple times.

I need this because i had my own field type which is generated dynamically and i wan't to render the protoype for this field type multiple times.

{{ form_widget(form.vars.prototype, {'groups': groups}) | e }}

If i can't reset the rendered value i can't generate the prototype multiple times with dynamic values. I have to set the values with javascript or something else.