Eccentricity scores should be infinite when isolated actors exist

[oxy86]

When isolated actors exist in a network (and are not disabled) the Eccentricity (max geodesic distance to all other actors) of each actor is by default infinite.
The Eccentricity Report states that fact although it reports non-inf scores for all other actors (except the isolated) as if the isolated one was disabled by the user. This is misleading.