init_variables_3d - initialise 3D related stuff

INTERFACE:

    subroutine init_variables_3d(runtype)
    IMPLICIT NONE
INPUT PARAMETERS:
    integer, intent(in)                 :: runtype
DESCRIPTION:

Dynamic allocation of memory for 3D related fields via dynamic_allocations_3d.h (unless the compiler option STATIC is set). Furthermore, most variables are initialised here. LOCAL VARIABLES:

    integer                   :: rc