Fixed the verifiers in the default verifiers.
Added a utils class containing monotoring functions (e.g. memory usage)
The generation of all the initials states is now in GraphSimulator
bugfix: the initial states were not verified during the proof.
bugfix: configureInitialGlobalStates: initial_states was not initialized
bugfix: illegal_states was not initialized
bugfix: incorrect condition (== instand of !=)
bugfix : the equals function in Valuation was not correct
Main.main now offers a proof to test and verify the behavior.