Test without pressure perturbations, so 1D hydrostatic pressure
First test of variabel density in hydrostatic pressure calculation
Minor changes moist thermo, added correct (surface) ghost cells for hydrostatic pressure
Update hydrostatic pressure; calculate surface/domain top values from ghost cells, fill top ghost cell based on pressure domain top
Use temperature at half levels for integration hydrostatic pressure
Merge remote-tracking branch 'upstream/master' into 1dpress

Conflicts:
	src/thermo_moist.cxx
Cleanup + split hydrostatic pressure calculation into 2nd and 4th order routines
Optimization of the 4th order buoyanacy tendency routine
Minor optimization; split out the non-vectorizable iteration in calcql()
Added generic function to retrieve fields from thermodynamics, added thermo to cross-sections
Added lngrad option for thermodynamic variables, and added some checks to prevent illegal calling of cross options
Test for writing integrated quantities in cross-sections
Added checks on successful writing of slices, plus generic function checkSave to handle printed output
Kill model if cross-sections fail, plus some cleanup of cross.cxx
Merge remote-tracking branch 'bart/crossthermo' into thermo

Conflicts:
	src/thermo_dry.cxx
Put the proper retrieval function in the dns statistics