Provide useful helper methods in BasicProblem

[abeham]

It would be helpful if BasicProblem could offer a couple of helper methods:

• Tuple<Individual, double> GetBestIndividual(Individual[], double[])
• List<List<Tuple<Individual, double[]>>> GetParetoFronts(Individual[], double[][])
• UpdateOrAddResult(string name, IItem value)

It is quite tedious to implement these over and over.

[abeham]

r15051:

• Implemented GetBestIndividual as public static and protected method in SingleObjectiveBasicProblem
• Impblemented GetParetorFronts as public static and protected method in MultiObjectiveBasicProblem
• Implemented AddOrUpdateResult as public method in ResultCollection

[mkommend]

Reviewed r15051.

I am OK with the changes in the ResultCollection and SingleObjectiveBasicProblem as these are only minimal. However, ParetoFront calculation and domination are rather lengthy and spread throughout HL at various locations. It would be better to extract those in a separate utility class (related to #2592 comment 15).

[abeham]

r15080: Moved pareto front calculation from MultiObjectiveBasicProblem to a new class DominationCalculator<T>. Changed FastNonDominatedSort to use the new class.

I tested the changes with your NSGA-II results and others and given the same seed the results come out exactly the same as before.

[mkommend]

r15086: Renamed individuals to solutions in DominationCalculator to be consistent with other methods. r15087: Reverse merge of unrelated changes r15086 in CheckedItemListView.

[mkommend]

Reviewed r15080.

[abeham]

r15109: merged r15051,r15080,r15086,r15087 to stable