Eastern Europe 1.8 provinces

Reorganized provinces in Ukraine, Belarus and Russia for the 1.8
province changes. Replaced custom nations, Kiev, Chernigov and Ruthenia
(Galicia-Volhynia), with the standard nations added in 1.8.
Western Europe 1.8 provinces

Reorganized provinces in Iberia, France and Scandinavia for the 1.8
province changes. Added nations Valencia (Iberian taifa) and Rouergue
(Southern France).