Pop growth tweaks

-The return of custom population growth! Pop growth curves are now back to their beta values, where base growth is fairly low and heavily influenced by modifiers from population capacity and techs

-Increased overpopulation penalty and birth rate penalty from literacy, once again to attempt to rein in runaway population growth

-Rebalanced negative market access state traits so they are all either -5% or -10%
-Reduced birth rate bonus from being under historical target population further, to reduce early pop growth
-Added 5% market access price impact modifier for coastal states

-Reduced Bolivia's gold mines a bit
-Added some Bananas to Cajamarca

-Added missing Amazon River trait to some states
-Added a few more gold mines to Peru

-Changed high pop and low pop modifiers from +100% and -25% to +50% and -50% since my attempts at changing base pop growth have been unsuccessful so far

-Added generic starting armies for some larger countries that didn't have any defined

-Rebalanced Brazil's starting buildings
-Reduced rubber plantation requirement for developing the Amazon and gave each rubber state at least 10 rubber plantations

-Fixed American migration JE creating huge amounts of errors from its tooltip due to missing its variables (they are now created at game start)
-Fixed starting buildings in Ceylon