/**
	 * function register
	 * Registers a plugin action for possible execution
	 * @param mixed A reference to the function to register by string or array(object, string)
	 * @param string Usually either 'filter' or 'action' depending on the hook type.
	 * @param string The plugin hook to register
	 * @param hex An optional execution priority, in hex.  The lower the priority, the earlier the function will execute in the chain.  Default value = 8.
	**/
	public static function register( $fn, $type, $hook, $priority = 8 )
	{
		// add the plugin function to the appropriate array
		$index = array($type, $hook, $priority);

		$ref =& self::$hooks;

		foreach( $index as $bit ) {
		    if(!isset($ref["{$bit}"])) {
		    	$ref["{$bit}"] = array();
		    }
		    $ref =& $ref["{$bit}"];
		}

		$ref[] = $fn;
		ksort(self::$hooks[$type][$hook]);
	}