Added superoperator support, colorblind mode to hinton().
Added superoperator support, colorblind mode to hinton().

anubhavvardhan/qutip,zasdfgbnm/qutip,qutip/qutip,anubhavvardhan/qutip,cgranade/qutip,cgranade/qutip,zasdfgbnm/qutip,qutip/qutip