Improve status output to show ban list shortcodes and if a list is read only or not

[Cadair]

Unless I am missing something (very possible) I can't see an easy way of listing the shortcodes that it is possible to use when creating a new rule.

I would be useful if there was a way of listing all the ban lists, which showed the short codes, and also indicated if that list is read only (i.e. one you don't control but have subscribed to) or read / write.

Would it make sense to extend the status command with this information? From a look around the BanList source, that doesn't seem to know if the list is read only or not, but presumably that wouldn't be that hard to add to that class?

[turt2live]

First half is done by #312