TestF is a test on a square ice sheet.
The bed contains a large bump on the middle. 
The slip ratio of the bed varies from 0 to 1.
Spc the grid on the bed for 0 slip.
Periodic boundary conditions are applied on the boundary.
It is an prognostic test to see the influence of the bump on the velocity and the surface.
The viscosity must be the same during all the test, so we need to comment the update of the viscosity.
Comment UpdateFromInputs in Penta.cpp and/or Tria.cpp to do so.
