v = vrml_ellipsoid (moment, col) - Ellipsoid

moment : 3x3 : Define elipsoid by x'*moment*x = 1
or      3   :  use diag(moment)
or      1   :  use diag(moment([1,1,1]))   default : eye(3)

col    : 3   : Color                        default : [0.3 0.4 0.9]