Seed blocking in setup

[ambitious-octopus]

As @mariopaolucci proposed, might be useful to lock the seed during setup and then release it during the step. The goal of this modification is to eliminate the effect of setup at runtime.

[mariopaolucci]

It would improve comparability much. But we must be certain that the seed chosen is itself "typical." It is a kind of recursive problem if you include strong dependence on initial values.