Ignoring/Blocking a user does not prevent them from joining a game

[GrantBartlett]

Problem:

• You can ignore users, but it does not prevent them from joining your hosted game.

Solution:

• Check a user is in the host's ignore list, if they are, don't allow the user to join.

Things to check:

1. Check all users in the lobby have ident info assigned when a user first joins the main channel.
   E.g. neogrant joins #cncnet-yr - does he have all ident info of every user in the channel, or just nicknames. (If we don't have ident info, we need an extra irc call (DoWhoQuery) or similar at the start to fetch all info on irc users so the client knows it all (So IRCUser isn't null)

2. Add a check before a user joins the game lobby that the ident is not in the ignored list and prevent them from joining if they are. See GameChannel_UserAdded in CnCNetLobby.cs