Please add support so that in dynmap it displays the towns open status.

This is a toggle feature (/town toggle )

your already supporting the other toggles: (well most of them)
explosion - yes
fire - yes
mobs - yes
public - yes
pvp - yes
taxpercent - no
open - no

I personally don't care about taxpercent support but someone else might.

Sounds good - I'll add it soon.