Added a few more conditions to prevent strange assimilation once a state goes post-national.
Also fixed a few typos in decision text
-Added conditions so both Jews and Afro-Americans cannot be accepted once the USA/any country has become multicultural
this is to prevent a situation where you only have a few multicultural pops in you country, less than Jews, as an example, then more pops will assimilate to be Jews than multicultural, and this process speeds up over time which can make some strange outcomes.
-As an example of a situation described above, Japan in my testing became a post-national state, but only a tiny island became multicultural, so Jews who immigrated into japan assimilated all the other immigrants and the Japanese before any multicultural pops could migrate for them to assimilate into
So I decided it works best to have everyone equally forced into multicultural assimilation as soon as it is possible to prevent these sort of situations.
