Hi,
In this mail you can find batman-adv initscript updated to work in this way and the batman-adv library file that must be located in /lib/batman-adv/.
I liked the idea of having hotplug hooks to restart the batman-adv configuration automatically. Generally, the scripts look good to me. You also changed its "coding style", e.g. $var -> ${var}. This does not look very OpenWRT-ish, therefore I would prefer keeping the current style. Any objections ?
Regards, Marek