Workaround "Serializable"

Class o.a.c.m.util.RandomPivotingStrategy is Serializable.

It is again questionable to have a class implement Serializable for no better reason than an instance of this type is contained in a class that is itself Serializable; indee it thus spreads like an epidemic in all the library.

In this case, the new UniformRandomProvider is not Serializable and this entails to have RandomPivotingStrategy contain custom serialization code...