Quentin 29/06/2021: SURFEX merge bugfix 8.1 :

23/07/2018  Correction from Arsene Druel for maj average
23/07/2018 Correction to read the 10-days periods in the PGD file (Rafife Nheili)
23/07/2018 Correction for PGD and NAM_DATA (Arsene Druel)
22/08/2018 Bug for parallel PREP & snow (array sizes) (Q. Rodier)
23/08/2018 Correction for LSPLIT_PATCH and LRESET_BUDGET=F (P. Samuelsson)
23/08/2018 Correction to have the same diagnostic output fields names with LSPLIT_PATCH=F
05/09/2018  bug fix from Aaron for MEB - initialisation
14/09/2018 Bugfix ISBA MEB (Aaron Boone)
25/09/2018 Error of dimension in allocation
10/10/2018 Bugfix ISBA MEB (Aaron Boone)
23/10/2018 Correction for upward compatibility for snow albedo
14/05/2019 BugFix: correction of H_TREE calculation by patch (impact only if H_TREE given in namelist, and if NPATCH different of 1 or NVEGTYPE)
21/06/2019 BugFix: correction of ZMASK used to initialise TEB variables when GTEB=FALSE in the extern file read for initialisation
23/08/2019 Bugfix NVEGTYPE_ECOSG / NVEGTYPE in read_nam_pgd_isba_meb (CEN)
17/11/2020 Bugfix: wrong initialisation of LIGNIN_STRUC and SOILCARB (when CRESPSL=CNT)
17/11/2020 Bugfix: correction for the writing of the variable ROOTFRAC in PREP file
29/03/2021 BugFix: YPHFILETYPE initialized twice, and missing initialization for YFERTFILETYPE
Updated to last commit (e826177a)