Update of Advanced Nuclear .16 fix. Adds customizable nuclear buildings.

One thing that may or may not be different: heat exchanger works at 15-20C*. Don't think that was my fault. Any unused power goes into the heat pipes, etc, but if you're drawing all the power the temperature of pipes/reactor won't change, as 100% of the power is being output by the heat exchanger (into turbines/storage tanks).

Cheat-y mod, as it's easy to make 1 turbine powered by 1 heat exchanger that uses 1 fuel cell to power your whole base.

Settings changed so instead of multiplying the 5.82 base megawatts of a turbine you can just set the megawatts. No weird ratios needed. Updated heat exchanger to transfer more power, and added maximum_temperature to turbine fluid_box so a turbine can use steam over 1000C.

Max throughput is limited to 10 GW for exchanger, turbine, heat pipe, and reactor (I think I changed the reactor). I'd need to change a line in the entity to raise it. If anyone asks I can bump it to 1000 GW (1 TW) or something.

* Caused by a lack of default_temperature and minimum_working_temperature.