This commit changes /login to no longer take command arguments. Instead, upon sending /login, you will enter an interactive "prompt", where your next OOC message will be interpreted as your login attempt (and will not be shown to other users). This prevents a typo from accidentally broadcasting your credentials to the entire area.
- Changes /login to take no command arguments, /login now sets a client state "is_logging_in".
- pktOocChat will now intercept a client's OOC message if they have this client state, and will interpret that as a moderator login.
- Adds the helper function loginAttempt() for handling moderator logins.
