Revert eee9e5c..baf006c

This rolls back to commit eee9e5c1a28cdf82f103bfc5619993be3accead1.
Non-legacy atmosphere compatibility changes

Removes more 1e-6 assumptions for cases where useLegacyAtmosphere =
False (atmospheric pressure in these cases depends on pressureCurve *
pressureMultiplier and has no lower limit)