Visualizes changes of values of the VertexLabeling by changing vertex colors appropriately.

E.g., #d = AnimatedVertexLabeling(A) #d[v] = 0 will color v cInitial.

The coloring used for d[v] = val - cInitial if val = 0,None,gInfinity - "blue" else

__init__ (
        self,
        theAnimator,
        initial=0,
        )

__setitem__ (
        self,
        v,
        val,
        )