Tried to move to just swapping sign on Z axis

Technically it *would* make a right-handed coordinate system. Doesn't
rotate properly in practice...
Revert "Tried to move to just swapping sign on Z axis"

This reverts commit cf23e904b904a0f8623076da16269c6a1b461e02.
Cleaned up compilation errors

Moon, Planet, and Star still (will) inherit from Celestial, but not yet.