HOLD: Optional crop and soil files (only for NASA-LIS-AquaCrop coupling)

[MaximeVdB]

This PR intends to make 'crop' and 'soil' files optional (by specifying them as (None) in the PRM/PRO file) and in this way allow external programs like LIS to set crop- and soil-related parameters directly (without needing to write input files which would then be read in by AquaCrop).

• [x] Passes the Perennial and Harvest tests and a selection of ~50 Europe tests, for the combinations DEBUG=0/FORTRAN_EXE=1, DEBUG=1/FORTRAN_EXE=1 and DEBUG=1/FORTRAN_EXE=0, both with the Singularity image and with `foss-2018a.
• [x] Split up LoadCrop procedure as well.
• [x] Re-run above tests (all passed)
• [ ] Test with LIS (-> Michel)

[mbechtold]

Looks good to me, only Zrni seems not be set for external use. I think also LoadCrop needs to a split up into LoadCrop and LoadCropProcessing, e.g. this is a processing step after input reading. call SetCrop_CCo((GetCrop_PlantingDens()/10000._dp) &

• (GetCrop_SizeSeedling()/10000._dp)) call SetCrop_CCini((GetCrop_PlantingDens()/10000._dp) &
• (GetCrop_SizePlant()/10000._dp))

[mbechtold]

The LoadProfileProcessing works nicely with LIS when working around the above issues (hardcoded version number and added GravelVol part). Will check the LoadCropProcessing later today!

[MaximeVdB]

(Marking as WIP since we're postponing the testing of the crop part)