Corrected bug in set_contact.F

[arango]

• Corrected a bug in set_contact.F when using WET_DRY. The variables Rcontact(cr) % Lweight, Ucontact(cr) % Lweight, Vcontact(cr) % Lweight needed to be initialized to their respective unmasked values (Lweight), even if WET_DRY is activated. The horizontal interpolation weights are rescaled in mask_hweights for the wet/dry cells. However, the horizontal weights need to be initialized in the permanent wet cells, which were not when WET_DRY is activated. Similar initialization is needed for the quadratic interpolation weights: Rcontact(cr) % Qweight, Ucontact(cr) % Qweight, Vcontact(cr) % Qweight. Many thanks to John Warner for bringing this to my attention.

• Corrected spelling of FORWARD_MIXING in mod_mixing.F when initializing mixing coefficients AkvG and AktG:

  #if defined FORWARD_READ && defined FORWARD_MIXING && defined SOLVE3D && \
      (defined TANGENT || defined TL_IOMS || defined ADJOINT)
       ...
  #end
  

  Many thanks to Gordon Zhang for ​reporting this typo.