Is it possible to start a new pvp scenario on a headless server or do I have to start it from a client and upload the savegame to the server? If possible, where do I edit settings like 'Duplicate starting entities' and win conditions?

Much thanks!

Well and there is the update (at least experimental). Thanks for your answers anyways!

I am thinking about buying Factorio, but since I have kind of busy weeks ahead I wanted to wait for the 1.1 update. Are releases of patches announced some time ahead or just dropped out into the world?