Philippe 07/01/2021: IO: remove GCLOSE_OUT variable/dummy argument (lopened field of tpfile datatype can be used instead)

This is incomplete for the moment. MesoNH must always be compiled with this key for the time being.

Philippe 06/01/2021: IO: add coordinates for dimension variables in diachronic files (not all yet done)

(cherry picked from commit fcebfc18)

Philippe 17/12/2020: Write_time_coord: generalize to vector of dates and add management of date intervals (conform to CF conventions)

Philippe 15/12/2020: menu_diachro: more intelligent ygroup allocation (waste less memory + no more risk of access out of range)

Philippe 08/12/2020: budgets: modify group_name management (in order to merge different times in further commits for netCDF files)

Philippe 07/12/2020: add support for partial write of fields (optional argument: koffset, not all subroutines, no LFI spport)

Philippe 07/12/2020: add CLEANLIST1D_ll subroutine + use it to correctly deallocate associated memory

Philippe 07/12/2020: IO: add support for Z-split files in IO_Field_partial_write_nc4_X2 + create IO_Select_split_file subroutine

Philippe 26/11/2020: IO: remove dead code (compatibility of dates with old MNH, not working anymore)

Philippe 24/11/2020: rename NMNHDIM_BUDGET_MASK_TIME -> NMNHDIM_BUDGET_TIME and time_mask -> time_budget

Philippe 13/11/2020: IO: improve CF compliance (add missing unit, does not write empty standard_name)