[sugestion] - Add forum URL to stylesheet links

Like the subject says, all href's that indicate the location of the .css file should be prefixed with $pun_config['o_base_url'].
The reason is that if you install punBB inside a subdirectory and integrate the forum with another site, the href will always point to the correct location.

I believe the correct line should be:

<link rel="stylesheet" type="text/css" href="<?php echo $pun_config['o_base_url'].'/style/'.$pun_user['style'].'.css' ?>" />