Validation of sac-cuda Using a 3D Flux Tube with Fully Stratified Quiet Solar Atmosphere

Revision 179  - demonstrates good agreement with solar flux tube test case

1. To check fixed boundary conditions

Here we will need to propaget updates to all of the models

(basically change the line which calls the boundary and its initialisation)

als init.cu changed

and cufinish in update.cu

2. Adaptive time steps

maximum routine are required for the following

           computation of maximum viscosity --- see getdtvisc_parallel in nushk1.cu

and   hyperdifvisc5l_parallel in hyperdifvisc1l.cu  (also the corresponding right component)

3. computation of maximum wave speed