LR-99: Battle Engine v1

Suggest making this a dictionary of dictionaries. Something like this:

```
REGION_MONSTER_DISTRIBUTION = 
{ 
    RegionType.ERIADOR : { Nazgul : .1 },
    RegionType.BARROW_DOWNS : { BarrowWight : .1, KingOfTheBarrows : .9 }
   ...
}
```

This will greatly simplify some of the logic in your monster factory. (You will be able to look up your region in the above dictionary instead of having separate if statements for each region). We can sit down and look at this sometime if you want.