Dynamically update guessed solution model

[Verdict7]

The guessed model only changes in one variable for every contraction. It might be faster to guess a solution in the beginning and update the model every time the interval of a variable changes. This way the model is always present and does not have to be recalculated every time. Also: It might be possible to check if all constraints are satisfied more often, which might reduce the overall computation time.

[kperun]

@Verdict7 I think here, it would be more beneficial to separate the methods. We need something like guessAssignment() and checkAssignment(), so we can incrementally check and update our model.