More Realistic POP growth

Beta V 0. 2. 5 This is a rework of the population growth model in Stellaris with the goal of changing the pace and keeping the amount of POP down to a level where game performance are maintained. The intention is that POP will grow much slower at the beginning of the game and that growth later in the game still will feel somewhat meaningful. The main change is that small planets with low population can't really grow on it's own and will rely on the migration mechanic to grow through the first stage to become a developed world. Changes from version 0. 1 Huge changes to the mod, especially in terms of what the AI can do with the game. I have integrated allot of the changes from Starnet AI that I liked and then added allot of my own changes and most importantly support script that help the AI transition planets from colonies to core and capital planets. The AI even can build Ecumenopolies now. I will also teach the AI how to terraform planets if they need to do that, but that is a much later project. In regard to population growth and general changes it should feel roughly like before just that population growth now are slower in the first 100 years... you generally end up at around 300-400 POP after about 100 years. Planets generally go through these phases... New Colony 1-5 POP, Early rural 5-11 POP, Rural 11-17 POP, developing world 18-39 POP, main world 40-79 POP, core world 80-124 POP and capital world at 125+ POP. Your first two to three colonies should grow to decent size relatively quickly and be more or less self sufficient in terms of POP growth. After this a second and third wave of colonization will be quite slow to grow as new under developed colonies receive less population than small rural worlds that are small enough to still be a frontier world but large enough to provide security and prosperity to new settlers. Another major change is how you unlock building slots... you no longer unlock them through building cities. This is too much of a gamey exploit f