Philippe 03/05/2018: IO: check if NAM_BACKUP namelist is present and that the list of valid backups is not empty

 Conflicts:
	src/MNH/spawn_field2.f90
	src/MNH/spawn_grid2.f90
	src/MNH/spawn_pressure2.f90
	src/MNH/spawn_surf2_rain.f90

Philippe 19/04/2018: IO: add possibility to choose directory for outputs, backups and diachronic files

* REQ_TAB and T_TX2DP too small if less processes than split files
* missing broadcast if split files (deadlock if IRESP/=0)

# Conflicts:
#	src/configure

Philippe 10/04/2018: lfi2cdf: take into account previous commits on dimension variables + bug correction on NKMAX

* treat more correctly datetime variables from LFI files
* pass HPROGRAM_ORIG at closing and not opening of file

Philippe 05/04/2018: IO: set all (except if in TFIELDLIST) SURFEX variables to be not time dependent (temporary?)