Scrambled Antarctica [RF+GS+NFP] 10.1

Convenience so the map mod doesn't have to be disabled when playing other maps. No changes to map.

Terrascape refreshed for better balance and aesthetics:
1. Use radial variance fractal for ice shelf, terrain and feature generation.
2. Reduce tundra % for realism (and to prevent Canada from being too OP on this map).

Minor bugfix to ice shelf generation in GS. Little to no impact. No impact on land generation.