Romancing SaGa level system reform

Basically that, I upgraded Michael's leveling system.

Before, it was kinda the Final Fantasy II model, where if you defend alot, you are upgrading Vit, if you attack alot, you upgrade Str, if you use magic alot, you upgrade Mag.  And like, MP and HP upgrade from those things being critical in battle.  But after playing a game called Alliance Alive, I decided that a far simpler method was just doing a comparison between your HP/MP/Str/Vit/Mag and your opponent. If they have more, you are fighting a stronger opponent, and you have a random upgrade chance.