Both default skins spell the chin width key chin_13. skinchanger only
knows chin_1 through chin_4, so the value never reaches the ped and the
key is stored as junk in users.skin.
It also breaks the ped. SetFace reads every feature through
Normalise(weight, 10), which divides, so a missing chin_3 raises
"attempt to perform arithmetic on a nil value" at feature index 17.
Everything after that in ApplySkin is skipped: the remaining features,
the eye colour, the head overlays, the components and the props.
Selt