#108: fix confirmation screen always popping up when using Itemswapper on server

[AdvancedWipe]

• add a cache file which saves the ip-address of the server the player is currently on, if the player accepts the warning. They will no longer get the warning for this server
• if the player denies the warning (will not accept), the mod will be disabled for this server. If the player now presses the hotkey, a message will be displayed that they disabled the mod for this server.

[tr7zw]

There should be a checkmark/extra button for permanently accepting an option.
Some other things:

• perma disabling the mod for a server with no way to undo it(except for deleting the line in the file) might not be a good idea. Keeping the "no" option only for the current session might be better
• Showing a small info in the actionbar/chat when the mod is still not on the server and the local file was used to skip the confirmation screen might be nice(so just once on the first use each play session)