Enable offline (disconnected from AP server) play

[budak7273]

• Store most data as part of the save
• Keep track of what has/hasn't been sent in the save file
• Send/receive when connection is established again later

Problem cases:

• Should local portals keep working or require connection to server

[Jarno458]

ATM portals do not work to send to yourself in offline mode, i think its fine, maybe a reason to fix your connection