Add more start locations for MP

[wbykos]

Hi.
It's really needed for multiplayer if we want start with separate bases and dont want build one base. And possible setting, distance between start locations for trains usage :3

[FishSandwich]

I think something like this is already planned for 0.12, going by this post by kovarex: https://forums.factorio.com/forum/vie ... 054#p63828

This doesn't confirm anything, but it seems logical to me.