~CR~ Uses/adapts new active mutation system: grants the ability to sprint and shout.

Renames 'mutations' menu to 'abilities and mutations' menu.
Gives all starting characters a pair of free activatable traits that allow them to sprint and shout.
Shouting just makes noise. It's a weaker version of the extant shouting mutation power.
Sprinting reduces movement cost, burns fatigue, thirst, and hunger. When you sprint you eventually become winded and stop being able to run until you rest, this is based off of your strength attribute.

These numbers probably still need to be tweaked a bit further, and there's a *lot* of little improvements to the system to be made, but I wanted to put this up now before I let it fall too far behind.

One caveat: I've not figured out how to give old saves the new base traits, since everybody's supposed to have these. Any information/assistance on this would be very much appreciated.
Like I said, there's plenty of room for improvement. I'm still not sure how the deactivate_mutation command works.