Changed CalculateFinalValue() to deal with Flat and Percent modifiers

CharacterStat.cs

private float CalculateFinalValue()
{
    float finalValue = BaseValue;

    for (int i = 0; i < statModifiers.Count; i++)
    {
        StatModifier mod = statModifiers[i];

        if (mod.Type == StatModType.Flat)
        {
            finalValue += mod.Value;
        }
        else if (mod.Type == StatModType.Percent)
        {
            finalValue *= 1 + mod.Value;
        }
    }
    // Rounding gets around float calculation errors (like getting 12.0001f, instead of 12f)
    // 4 digits is usually precise enough, but feel free to change this to fit your needs
    return (float)Math.Round(finalValue, 4);
}