A small update to fix a couple rare but nasty bugs and add some small tweaks:

• Removed the mapping of the "C" key to spawning the "superpredator" -- an abandoned feature from ancient times that crashes the game
• Capped the growth bonus from ideal temperature -- if the math rounded out wrong, critters could grow to massive size and immediately die, leaving a gigantic corpse
• Default setting for brain mutation rate lowered from 10% to 3.5%
• Default setting for Phenotypical Speciation changed to "Off"
• Nuts no longer derive their energy content from the fruit nutrition setting