Create residual viscosity package +rv and generalize the ResidualViscosity class - Generalize residual viscosity, by passing user-defined flux and calculating the time derivative outside of the update. - Create separate RungekuttaRV specifically using interior RV updates - Separate the artifical dissipation operator from the scheme AdvectionRV1D so that the same scheme can be reused for creating the diff op used by the ResidualViscosity class

% Returns true of obj is any of he types in the cell array types
%    b = isAnyOf(obj, types)
function b = isAnyOf(obj, types)
    for i = 1:length(types)
        if isa(obj, types{i});
            b = true;
            return
        end
    end
    b = false;
end