Local account-IP check

[misandrie]

Due to @space-wizards reading authentification logs the launcher needs an opt-in system to check if the user is reusing an IP already associated with a different account and deny authentification if the IP is already taken and ask to confirm if its a new one.
Can be integrated with MarseyHide.

The idea:

• User has 2 accounts: A, B
• User has logged to A and B from two different IP's
• If configured - Refuse log-in to account A from an IP belonging to account B
• If the user registers account C and uses a never before used IP - assign IP to account C.
• If a new IP is used to connect to an account with an already used IP - ask to confirm and add to list if allowed

The table of Account-IP should be viewable to the user with a third column providing a user-set comment.