Existing case did not properly converge and suffered slow convergence
with the water level failing to reach an equilibrium. A slight rise in
the channel appears to help the water level reach an equlibrium when the flow
rate over the rise matches the inlet flow rate.
The standard/previous general symmetry type is now named symmetry
both in class and lookup name for consistency. The rigorous
symmetryPlane type is needed for moving-mesh cases in which the
motion it constrained by one or two planes.
