[2.1.*] Reduced Ship Upkeeps

(2. 1.* version of my original Reduced Ship Upkeeps mod!) This mod does as it says: reduces the upkeeps of ships. A lot. Like... 75% a lot. So no more 2 minerals for 1 corvette. One. Corvette. You will now be able to actually afford building anything in your space... because how else are you supposed to acquire a steady enough income and maintain a decently sized fleet to avoid becoming space chow for your local Devouring Swarm? (of whom will also have reduced upkeeps, and likewise with the rest of your neighbors) No new games required: simply enable mod and play an existing save. Say hello to your new minerals and energy! Disable to see how dirt poor and worse off you'd be with vanilla upkeeps!