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?)

Philippe 05/04/2018: IO: modify IO_SET_KNOWNDIMS_NC4, IO_WRITE_COORDVAR_NC4 and IO_WRITE_FIELD_ATTR_NC4 to support files from all programs

This allows to write coordinate variables in all files and with all programs (see also next commits)

needed to manage correctly domain number when writing dimension variables

because they are often needed later (and they do not consume a lot of memory)

Philippe 29/03/2018: problem correction in Rules for gfortran: do not replace AINT by INT (AINT is for reals, INT for integers)
This was the origin of problems with management of XUNDEF in SURFEX
because XUNDEF can not be represented by a standard integer

+ remove temporal_lt function

Philippe 28/03/2018: replace TEMPORAL_DIST by DATETIME_DISTANCE and ADD_FORECAST_TO_DATE and SUBTRACT_TO_DATE by DATETIME_CORRECTDATE