Fix AI assignments / names

[historic_bruno]

When an AI player tries to send a chat message, it is listed only as "Unknown player". I think that's just one symptom of AI player assignment being a bit hacky. They should be handled about the same as a human player, perhaps using the AI name as their own (i.e. "Demobot" instead of "Player 2") in the UI and also being able to send chat messages. If all the AIs are named "Player #" then it's easy to forget which is which, for comparison purposes.

We could even have a database of historical names to be chosen at random for the AIs, adding some personality.

[Philip Taylor]

Part of the reason for the current approach is that it's nice to have a human and AI assigned to the same player, for developing and testing AI scripts. But currently you can only do that via autostart arguments, which is probably okay - the standard game setup process can assume one human or AI per player slot.

Also it'd be nice if you could disconnect from multiplayer and have an AI player take over, instead of being totally helpless or automatically defeated, and then reconnect and retake control, so that people with unreliable networks or frequent game crashes can cope better. I'm not sure how that would interact with this player assignment issue.

(I don't really like the current design of the human player assignment system at all, but I don't know if it's better to extend it to properly support AI players or to fundamentally redesign it (I don't currently know what would be a better design).)

[fcxSanya]

Replying to Philip:

Also it'd be nice if you could disconnect from multiplayer and have an AI player take over

Unless AI will assign all of your workers and resources on creating some useless Statue_of_AI_Majesty :) Seriously, this should be very careful AI in this case.

[wraitii]

Fixed in various ways in various former revisions.