Pokemon Natures  refactored and corrected

PokemonNature refactored to follow pattern
PokemonNature field added for disliked taste
ClassicNatures use new construction of PokemonNature
ClassicNatures data corrected where appropriate
ClassNaturesHarvester. script added, used to generate ClassicNatures
Flesh out the @depreciated rationale.
Merge pull request #2 from JPokemon/nature-changes

Pokemon Natures refactored and corrected