Liberating "enemy" systems

[Spocks-cuddly-tribble]

already ordered task forces keep their mission. So when a colony ship is underway, you need to cancel the ordInfo order.

I see, thank you. So no need to update this code, since it can't fix this BotF AI glitch (without editing AI files in the savegame).

The abort code for AI colonize tasks needs a max pop 0 check, since vanilla BotF doesn't know this case for unpopulated systems (supernova works only for populated empire systems).