CCPP-ize Rayleigh Friction

[Katetc]

I can work on this again! First step, learning the process with a simple parameterization. Rayleigh Friction, coming soon!

!---------------------------------------------------------------------------------
! Module to apply rayleigh friction in region of model top.
! We specify a decay rate profile that is largest at the model top and
! drops off vertically using a hyperbolic tangent profile.
! We compute the tendencies in u and v using an Euler backward scheme.
! We then apply the negative of the kinetic energy tendency to "s", the dry
! static energy.
!
! calling sequence:
!
! rayleigh_friction_init initializes rayleigh friction constants
! rayleigh_friction_tend computes rayleigh friction tendencies
!