Set some variables related to output

INTERFACE:

    subroutine prepare_output(n)

DESCRIPTION:

This routine check whether output should be written at the current time step. If this is the case, the model time is written to a string for display on the screen.

USES:

    IMPLICIT NONE

INPUT PARAMETERS:

    integer, intent(in)                 :: n

REVISION HISTORY:

    Original author(s): Karsten Bolding & Hans Burchard
    See output module