init_domain() - initialise the computational domain

INTERFACE:

    subroutine init_domain(input_dir,runtype)
    IMPLICIT NONE

DESCRIPTION:

This routine is responsible for setting up the bathymetry and the grid information.
The following steps are done in $init\_domain()$:

1:	partition of the calculation domain - important for parallel runs
2:	reading bathymetry and grid information through the generic subroutine $read\_topo\_file$
3:	optionally set minimum depth in regions
4:	optionally adjust the depth in regions
5:	optionally adjust the depth in regions
6:	calculate the mask for T-points
7:	optionally adjust the mask in regions
8:	read boundary information and adjust masks
9:	calculate masks for U-, V- and X-points
10:	calculate additional grid-information - like $latu$ and $latv$
11:	calculate metrics - i.e. all necessary grid-spacings
12:	calculate Coriolis parameter - can be constant or spatially varying

INPUT/OUTPUT PARAMETERS:

    character(len=*)                    :: input_dir
    integer, intent(in)                 :: runtype

REVISION HISTORY:

LOCAL VARIABLES:

    integer                   :: rc
    integer                   :: np,sz
    integer                   :: i,j,n
    integer                   :: kdum
    character(len=PATH_MAX)   :: bathymetry               = 'topo.nc'
    integer                   :: vel_depth_method=0
    character(len=PATH_MAX)   :: bdyinfofile              = 'bdyinfo.dat'
    character(len=PATH_MAX)   :: min_depth_file           = 'minimum_depth.dat'
    character(len=PATH_MAX)   :: bathymetry_adjust_file   = 'bathymetry.adjust'
    character(len=PATH_MAX)   :: mask_adjust_file         = 'mask.adjust'
    namelist /domain/ &
              vert_cord,maxdepth,                               &
              bathy_format,bathymetry,vel_depth_method,         &
              longitude,latitude,f_plane,openbdy,bdyinfofile,   &
              crit_depth,min_depth,kdum,ddu,ddl,                &
              d_gamma,gamma_surf,il,ih,jl,jh,z0_method,z0_const,&
              check_cfl