Allow to get permitions for section != 'component'

This will allow to set ACL different groups based on category permissions, for example:
access.xml
	<section name="component">
		[...]
	</section>
	<section name="category">
		<action name="roles.list" title="roles list" description="" />
		<action name="roles.manage" title="roles manage" description="" />
	</section>

view.html.php (view of a generic component)
[...]
$this->canDo = JHelperContent::getActions('com_componentname', 'category', $item->catid);
if (!$this->canDo->get('roles.manage')) {
            JError::raiseWarning(404, JText::_('JERROR_ALERTNOAUTHOR'));
            $app = JFactory::getApplication();
            $app->redirect('index.php');
}
[...]