* replace FMREAD/FMWRIT by IO_READ/WRITE_FIELD
* modify SET_CONFIO_ll call in mnh2lpdm.f90
* use TZPGDFILE for read_chem_data_netcdf_case.f90
* declare TZATMFILE when necessary

Warning: not fully tested

+ removed some LEN=LEN_HREC for unrelated variables

Philippe 18/08/2017: IO: use IO_READ_FIELD for several fields, IO_FILE_OPEN and IO_FILE_CLOSE for several files

* added IO_FILE_ADD2LIST subroutine and use it
* IO_FILE_OPEN now requires the file to be in the file list
* IO_FILE_FIND_BYNAME: added optional argument useful when checking
  that a file does not yet exist
  + bug correction when filelist is empty
* added IO_FILE_PRINT_LIST subroutine (only for debugging)
* added TPTR2FILE structure to allow construction of arrays of
  pointers to files
* use IO_READ_FIELD for some 3D float arrays (in read_field.f90)
* OPEN_ll: added UPDATE_METADATA internal subroutines to treat file metadata

Conflicts:
	src/ARCH_SRC/CPL_WAVE/MNH/ground_paramn.f90
	src/ARCH_SRC/CPL_WAVE/MNH/ini_modeln.f90
	src/MNH/default_desfmn.f90
	src/MNH/goto_model_wrapper.f90
	src/MNH/ground_paramn.f90
	src/MNH/ini_lb.f90
	src/MNH/ini_modeln.f90
	src/MNH/modeln.f90
	src/MNH/read_exsegn.f90
	src/MNH/read_field.f90
	src/MNH/write_aircraft_balloon.f90
	src/SURFEX/ch_init_depconst.F90
	src/SURFEX/ch_init_emissionn.F90
	src/SURFEX/ch_init_snapn.F90
	src/SURFEX/init_surf_atmn.F90
	src/SURFEX/writesurf_snapn.F90