Juan 26/09/2017:interpol_field2d.F90, differencied error message :: SFX/NAM_IO_OFFLINE <=> MNH/NAM_PGDFILE

Merge branch 'MNH-53-branch' of mesonh2.aero.obs-mip.fr:/gitrepos/MNH-git_open_source-lfs into MNH-53-branch

(cherry picked from commit baada275)

It was already possible but LEN_HREC was missing in some places.

(cherry picked from commit e2fbb2b2)

J.P. Chaboureau & Juan 21/08/2017:surf_solar_slopes.f90, correction for tiny solar zenithal angle in R*4

Philippe 17/08/2017: bug correction: corrected field name for reading of droplet deposition (ACPRC->ACDEP)

Christine & Juan 11/08/2017: get_vegn.f90 , remove MNH (obsolete) version of get_vegn.f90 , good one in SURFEX

(cherry picked from commit 72baafd3)

Juan 30/06/2017: J.Escobar 30/06/2017 : Add activation of ZLIB compression in X2/X3 fields , if MNH_IOCDF4 == 2

Juan 28/06/2017: modd_surf_par.F90, for REAL4 put greater value for XUNDEF=1.e+9  <-> elsif problem with X/YHAT value == XUNDEF

Juan 12/06/2015 :zoom_pgd_cover.F90, Bug in SPAWNING in // , compute/update LCOVER in // with SUM_ON_ALL_PROCS

Juan 12/06/2017:read_exsegn.f90, M.Leriche 06/2017 for spawn and prep_real avoid abort if wet dep for aerosol and no cloud scheme defined

                                  Mai 2017 (M. Leriche) Get wet dep. sv in Meso-NH init file

Philippe 09/06/2017: IO: name of the variable added to the name of the written field and better comment (true comment + units)

(cherry picked from commit ab3bad9d)