Branch dev_r11615_ENHANCE-04_namelists_as_internalfiles_agrif. Changes to support [source:/NEMO/branches/2019/dev_r11613_ENHANCE-04_namelists_as_internalfiles] developments.
These changes enable sufficient support for allocatable, zero-dimension character variables defined using the:

{{{#!f
CHARACTER(LEN=:), ALLOCATABLE :: cstr
}}}

syntax. This is supported by:

1. Adding : as a valid length identifier at line 1028 in ''fortran.y'' (and then rebuilding ''fortran.c'' and ''main.c'' via `make -f Makefile.lex`)
2. Adding a `carrayu` entry to Agrif_Variable_c type in ''AGRIF_FILES/modtypes.F90'' where `carrayu` is declared as:
{{{#!f
   character(:)  ,                 allocatable :: carrayu
}}}
3. Ensuring correct deallocation of `carrayu` in ''AGRIF_FILES/modsauv.F90'' and ''AGRIF_FILES/modutil.F90''
4. Substituting `carrayu` in place of carray0 declarations when character length matches : for zero-dimension variables. This occurs twice in ''LIB/toamr.c'', e.g:
{{{#!CC
        if (!strcasecmp(var->v_dimchar  ,":") && var->v_nbdim == 0 )
        {
        sprintf (tname_2, "%% carrayu");
        } else {
        sprintf (tname_2, "%% carray%d", var->v_nbdim);
        }
}}}
Any such character variables must be allocated by the user. Typically this is done with lines such as:
{{{#!f
      IF ( .NOT. ALLOCATED(cdnambuff) ) ALLOCATE( CHARACTER(LEN=kleng) :: cdnambuff )
}}}
making AGRIF accept the `CHARACTER(LEN=kleng) :: construct` within the `ALLOCATE` statement was beyond my skills. Fortunately, for the current purpose, this
isn't necessary since such allocations only occur within utility routines in which the appropriate tabvar has been passed down. So:
{{{#!f
!$AGRIF_DO_NOT_TREAT
      IF ( .NOT. ALLOCATED(cdnambuff) ) ALLOCATE( CHARACTER(LEN=kleng) :: cdnambuff )
!$AGRIF_END_DO_NOT_TREAT
}}}
avoids the issue.