Web Browser support for running demonstrations

[aquatiko]

I was having some trouble running the Color separations and the SVD demonstration on IJulia, so I added a little tweak to interact on a web browser. i.e:

using Interact, Mux
ui = @manipulate for k1 in 1:n, k2 in 1:n, k3 in 1:n
    colorview(RGB,
              rank_approx(svdfactors[1], k1),
              rank_approx(svdfactors[2], k2),
              rank_approx(svdfactors[3], k3)
              )
end
WebIO.webio_serve(page("/", req -> ui), 8111) # serve on localhost:8111

I think it would be helpful for someone stuck at the same step to run the demonstration on IJulia. Would be happy to add a PR if needed.