ProjectConfiguration adaptation to prevent sessions starting for bots

gistfile1.php

		// avoid session starting for bots
		$agents = array(
			'googlebot',
			'yahoo! slurp',
			'baiduspider',
			'sosospider',
			'bingbot',
			'nagios-plugins',
		);

		foreach ($agents as $i => $agent)
		{
			$agents[$i] = preg_quote($agent, '/');
		}

		if (preg_match('/' . implode('|', $agents) . '/i', $_SERVER['HTTP_USER_AGENT']))
		{
			sfConfig::set('sf_factory_storage', 'sfNoStorage');
		}