Changes

This commit is being made to keep the stats zt output from the
master branch inline with the output from the clubb_ghost_exorcism
branch. In short, the only change is that the value of
a couple of inputs relative to wpxp turbulent advection from
thermodynamic level 1 are set to 0 for stats output in order to
keep the master and ghost exorcism branches bit-for-bit with
each other. The output at those levels are not used in
any calculations and are unnecessary. However, this change
is technically BIT_CHANGING.

I am committing a bug fix to the code that calculates mixed Brunt
Vaisala frequency. The variable ice_supersat_frac was used directly
in calculations that are supposed to take place on a momentum level.
The fix is to interpolated ice_supersat_frac to momentum levels before
use. This commit is BIT_CHANGING.