UPDATED: Wigner colormap now has shift parameter
UPDATED: Wigner colormap now has shift parameter

The shift parameter allows for shifting the value at which the color
map begins to emphasize.  This is useful when the Wigner function has
small non-zero values due to numerical round-off or Hilbert space
truncation.

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