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

% [x,h] = get_grid(a,b,m)
function [x,h] = get_grid(a,b,m)
    % TODO: allow the interval to be a vector
    x = linspace(a,b,m)';
    h = (b-a)/(m-1);
end