Fix atmospheric scale heights

[NERVAfan]

Duna and Laythe have a smaller atmospheric scale height than Kerbin. This is backwards from how it works in the real world, where more gravity = smaller scale height.

(It's also affected by temperature and molecular weight, true, but for Mars the lesser gravity still means a bigger scale height, even though Mars' atmosphere is colder.)

[Stargate525]

I'd just be happy with a scale height that actually matches up between the listed numbers, the UI altimeter, and the timewarp indicator. They're close, but significantly off enough to truly annoy.