Changes

QuadTune: Create config file where a user can input "namelist" info about his obs and simulations.  Also add an example config file so that the user can keep multiple namelists.  Do minor refactorings.

For #910.

QuadTune: Rename "linSoln" to "globTuned" in order to denote the global simulation result after tuning.  Add docstrings to more functions.

For #910.

Clubb test correct gg (#1237)

* Updated the generalized vertical grid test to use the
run_bindiff_w_flags_config_core_flags.json file, which performs
18 overall flag configuration file tests and includes almost
every configurable model flag found in CLUBB core.

* Fixed a bug. This was caught by running the new hybrid PDF after
compiling with the gfortran debug compiler script.

* The CLUBB code requires l_min_xp2_from_corr_wx and
l_enable_relaxed_clipping to always have opposite values.

* Finally fixing the bug where Cx_fnc_Richardson needs to be interpolated
to thermodynamic levels in order to be used as C11_Skw_fnc.

* I fixed an issue with the generalized grid when the expldiff of rtm
and thlm is enabled.

* The variable gr now needs to be passed into subroutine pvertinterp
(which was formerly found in interpolation.F90) in order to generalize
the grid. This created a circular dependency, for grid_class references
interpolation, and now interpolation needed to reference grid_class
in order to use type grid. This road block prevented the model from
compiling. I moved subroutine pvertinterp to advance_clubb_core in
order to solve the problem.

* Moving the flag required editing the delimiters.

* I fixed a bug in the generalized grid test code that was resulting
in pdf_implicit_coefs_terms scalar variables not being read in
correctly for the flipped (descending) grid.

* Improved some error handling in clubb_driver.F90

* Fixed an issue where ascending and descending grids were producing
results that were not bit-for-bit to each other where centered
discretization was used. The issue occurred because 3 or more terms
were being added together in opposite orders between ascending and
descending grids. This fix ensures terms are added in the same order.

* Commiting changes to keep calculation order the same for additions
involving at least 3 terms from different vertical levels between
ascending and descending grids.`

* I removed bugs that were causing failures of the bit-for-bit
matching test (at -O0 optimization) between ascending and descending
grids. This group of fixes related to the code that calls pdf_closure
twice and calls the trapezoidal rule code.

* I have fixed the ascending vs. descending grid error for the situation
where l_partial_upwind_wp3 is enabled.

* I am removing the flag setting of l_mono_flux_lim_thlm to .false.
in flag group 15 of the ascending vs. descending grid tests.

Problem: Removing the constraints on thlm was causing one case (MC3E)
to blow up with a floating point exception in Morrison microphysics.
The issue was that a spike caused an extremely cold temperature to be
found. There is a line of code that takes the difference between
freezing/melting point temperature (273.15 K) and the temperature
at the grid level or sample point, multiplies it by constant, and then
takes EXP to that product. The large difference between temperature
and freezing/melting point, owing to the spike, caused a numerical
overflow to occur and the case to fail with a FPE.

Solution: There isn't any relevant code found in the monotonic flux
limiter that doesn't get tested if l_mono_flux_lim_thlm remains at
a setting of .true. The other parts of conditionals are covered
by setting l_mono_flux_lim_rtm to .false. The only parts of the
code unique to l_mono_flux_lim_thlm are the recording of stats
related directly to thlm. Thus, it makes sense to keep
l_mono_flux_lim_thlm set to .true. for the stability of the run
while turning off the other monotonic flux limiter flags.

* Updated the code to use break or return when clubb fatal error is
encountered, which is more consistent with the way CLUBB does business
now, then simply Fortran stop in place. This also allows the generalized
grid test to finally pass for all cases and all flag sets.