Change unit of OASIS time step and coupling frequency for LES

[s-poll]

The time stepping controlled by OASIS3-MCT and the coupling frequency between the component models is currently defined in seconds. Some high resolution (dx<100m) large eddy simulation (LES) need a sub-second time step for numerical stability. Unfortunately, the coupling period is an integer type in the namelist of OASIS3-MCT namcouple (further info OASIS user guide). One solution would be to define the coupling frequency in namcouple in tenth of seconds, or milliseconds and do the unit transformation in the component models. This is the current solution for high resolution TSMP simulation (dx<100m), but need changes in the component model source code and might also effect some workflows.