Added (very basic) spam filtering plugin support. Plugins can mark a message as spam by hooking into the spam check API, which is documented in functions.php. No spam checking functionality is built-in.

<?php

class Text_Wiki_Render_Plain extends Text_Wiki_Render {
    
    function pre()
    {
        return;
    }
    
    function post()
    {
        return;
    }
    
}
?>