Fixed DynamicPersistenceTrails::PairingTrailsVisitor to match the changes in StaticPersistence::PairVisitor
#ifndef __NUMBER_TRAITS_H__
#define __NUMBER_TRAITS_H__
template<class NumberType_>
class number_traits
{
public:
typedef NumberType_ NumberType;
static NumberType& normalize(NumberType& n) { return n; }
};
#endif