Have unpredictable map generation in multiplayer

[TheJJ]

In order to not reveal any information about the map except the actually discovered areas, the gameserver must not provide the seed used for the generation to the clients. Instead, only seen tiles/units/etc are transmitted in the state they were last seen. Great cheat protection :)

[timo-42]

this should be merged with the multiplayer proposal. And it is a must since I dont know how determinstic python3 floating point arithmetic is.

[janisozaur]

That's a nice idea.