Version 0.6.0: Factorio 2.0

• Update to Factorio 2.0
• Redo some (well, most...) of the graphics
• Many adaptions in data model
• Make double-electric-furnace research more expensive
• Change recipe: Double Furnaces (either type respectively) are now made from two normal ones
• Remove very old migrations because the last update was 3 years ago and we had to change so much for Factorio 2.0, that I now consider these even older migrations unnecessary baggage