wild_lake places a lot entities which are decided based on the biome. This diff moves those definitions to a JSON file which should make extension and maintenance easier. Would also get rid of two objects which were basically doing the same thing.
It also moves the camp entities to the JSON file. Celts in India just doesn't feel right. However, the entity changes are not yet included.
Unsupported biome error fix based upon JeHathor's patch at P140