Merging strategy for new release versions (CMIP6-compatible and INES interim release)

[jmaerz]

Hi @JorgSchwinger and @TomasTorsvik ,

PR related in preparation to NorESMhub/NorESM#466:

Required for CMIP6-compatible final version:

• migrate HAMOCC config settings to run time namelist settings #281
• Add capability to run OAE experiments with an OmegaA threshold #291
• Fix bug in powach.F90 C-isotope code #290
• potentially SIunits4hamocc #233
• transfer most parameters into mo_param_bgc #294
• Move main sediment parameters to mo_param_bgc #297
• Some cosmetic changes #299
• Remove dmspar variable #300
• Remove variable bolven from sediment code, consistent treatment of dms parameters #301
• Minor fixes for configuration and namelist creation #303
• New hamocc formatting #305
• Fix for omp bug found in the github actions #307
• Feature code cosmetics2 #308
• Exclude HAMOCC from compilation for cmp-flag ecosys=false #309 (currently expected as the final and last CMIP6-compatible version from the HAMOCC side)
• Draft v1.4.0 release #310 tagged release of CMIP6 compatible BLOM/HAMOCC

(Upcoming) PR for getting iHAMOCC ready for NorESM2.1 version (PRs are named, once they are opened):

• Merge master into beyond-CMIP6 branch #311 Merge master into beyond-CMIP6 & code cosmetics on beyond-CMIP6
• Properly declare and initialize bifrXX_ini and clean mo_biomod from growth_co2 #314 Some minor declaration, etc. issues
• Breaking CMIP6 backward compatibility through bugfixes - iHAMOCC ready for NorESM2.1 #315 Merge beyond-CMIP6 (incl. bug-fixes) back into master - making master ready for milestone NorESM2.1
  From cca8d11 onward, master is not backward compatible any longer for iHAMOCC and ready for NorESM2.1.

(Upcoming) PR for getting iHAMOCC ready for NorESM2.x version (PRs are named, once they are opened):

• Merge extended nitrogen cycle, M4AGO scheme and preformed Si tracer into master #269
• potentially add preformed silicate tracer

[jmaerz]

Notes for merging master into beyond-CMIP6:
Check fixes formerly carried out:

• DONE burial
• DONE OMP in sinking
• DONE alkalinity, etc. in sediment

Further changes to apply, once master is merged into beyond-CMIP6:

• DONE: wpoc, wopal, etc. as protected (via Fix for omp bug found in the github actions #307)
• DONE adapt OMP settings in sinking
• Properly declare and initialize bifrXX_ini and clean mo_biomod from growth_co2 #314 bifr13, bifr14

Changing opal dissolution rate in sediment will be carried out for a later tagged NorESM version