Removed public="false" on service sonata.block.templating.helper

Made sonata.block.templating.helper public so you can use it separately to render block.

	$blockHelper    = $this->get('sonata.block.templating.helper');

	// Build the vacancy block
	$vacancyBlockData = $this->getDoctrine()->getManager()->getRepository('AcmeBlockBundle:Block')->findOneByType('acme.block.service.vacancy');
	$vacancyBlock = $blockHelper->render(array(
		'type'      => $vacancyBlockData->getType(),
		'settings'  => $vacancyBlockData->getSettings(),
	));