METABOLIC BONUS FUNCTIONS

Used by the METABOLIC, SOLAR POWERED and NOCTURNAL attributes. For METABOLIC, the characters energy levels determine a bonus between -2 (no energy) and 2 (full energy) and apply this to update various attributes constantly.
For solar powered characters the return bonus varies from about -3 to 3, for NOCTURNAL characters the bonus is a flat 0 at day, 1 at night.