Move random biome system to a separate mapgen library.
Proposed library and directoryname agreed with FeXoR.
Make the rmgen/ biome agnostic by moving the biome constants in createForests to the randombiome globals.
Don't pass a non-randombiome constant in gulf of bothnia to the createForests function that expected a randombiome constant, refs rP14837, accepted by Grugnas.
Remove unused trivial unrecommended randomizeBiome function,
make Biomes autocompletable in the gamesetup chat, refs D852.
git-svn-id: https://svn.wildfiregames.com/public/ps/trunk@20127 3db68df2-c116-0410-a063-a993310a9797