add listbans command

[Jigoku]

Allows server moderators to list active bans within the server in-game.

Changes proposed in this request:

• /listbans
• Restricts to G(banlock) privileges (but maybe this would be better as PRIV_ADMINISTRATOR ?)

~~I did intend to also add user tracking (added by: person) etc, although couldn't get ipinfo to store it properly right now. Whether that's something to add later.~~

[Jigoku]

Now outputs the name of the person who applied the ban;

1: [ban] 192.168.0.69 (reason: trolling [unixfreak])
2: [ban] 192.168.0.42 (reason: more trolling [unixfreak])

etc

[qreeves]

• I think it is unwise to include the name of the person from the client's side, as this could be edited out by a malicious user.
• If a user is authed, it should probably include their authname.
• If you're going to add a list command for one thing, it's probably a good idea to do it for all the addcontrol types.
• When you change the network protocol, you need to bump GAMEVERSION in src/game/game.h.

[q009]

Any updates on this?