HPC-09_Gurvan — ZDF restructuration with reduced number of lbc_lnk call

[gm]

Context

Restructuration of all vertical physics packages (ZDF) in order to reduce the number of communication and suppress most (if not all) the key_zdf...

Implementation

1. remove avmu, avmv, keep only avm and use an average in the dynzdf_imp (_exp) modules (save mpp comm)
2. Define tau_i, tau_j, the surface ocean stress at t-point, and remove utau, vtau (stress defined at u- and v-point) to remove the communication phase on utau and vtau. This require to adapt the dynzdf modules.
3. create the zdf manager that encapsulate the computation of all module that modify avm and avt. ==>> only one communication phase on those fields at the end of the ZDF manager instead of one by ZDF modules. In the process, we also remove all the key_zdf... replaced by namelist variables.
4. simplification: introduce a generic routine to perform the inversion of a tri-diagonal matrix and use it in implicit vertical diffusion (DYN and TRA), in TKE and GLS, and in 4th order compact scheme (TRA and DYN).

[nemo]

Remove 'Development' type

[gm]

Incorporated in the dev_merge_2017 branch