Adds in a heat powered furnace that is faster with 2 additional module slots and 50% prod bonus.

I found myself unhappy with space age's requirement that you continue to use the electric furnace even in the ultra late-game and its problematicness of using it for quality due to its 2 module slots. It is heat powered because we don't have any heat powered machines in space age and different things are cool.

Building graphics by hurricane