Convert Kunena intallation to jQuery for J!3.x series

should be:

```
 };
	jQuery(document).ready(function() {
		jQuery('#kunena-toggle').click(function(e) {
			jQuery('#kunena-container').toggleClass('hidden');
			e.preventDefault();
		});
		jQuery('#kunena-component').click(function(e) {
			window.location.href='<?php echo JRoute::_('index.php?option=com_kunena')?>';
			e.preventDefault();
		});
		jQuery('#kunena-installer').click(function(e) {
			window.location.href='<?php echo JRoute::_('index.php?option=com_installer&view=install')?>';
			e.preventDefault();
		});
		window.kunenainstall();
	}); 
```