Expose the problem's operators list in a parameter

[abeham]

Currently the operators list stored in the problem is not visible and cannot be modified by the user. Sometimes however it makes sense to delete certain operators or add new ones.

[abeham]

r6938

• Added an *Operators* parameter in Problem
• Adapted KnapsackProblem, OnemaxProblem, SingleObjectiveTestFunctionProblem, TravelingSalesmanProblem, and VehicleRoutingProblem to derive from SingleObjectiveHeuristicOptimizationProblem<U, V>, renamed and marked old list as obsolete. Note that QuadraticAssignmentProblem, as well as the new DataAnalysisProblems already derived from that class. ArtificialAntProblem was not yet modified.
• Added some test lists and adapted SamplesTest
• Added plugin dependencies that the unit test was complaining about

[abeham]

Can you take a look at the changes? The change to use the new base class are similar in each problem. I removed the parameters, parameter properties and properties of those parameters that are already defined, renamed the operators list and made it an obsolete serialization property that would forward the call to Set to Operators.AddRange() and which would always return null. ArtificialAntProblem still needs to be modified, I'll do that after you tell me the changes are okay or you can do it yourself if you have the time.

[mkommend]

All the changes look good, except one minor mistake in the KnapsackProblem. The condition in the after deserialization hook should be equal zero instead of larger than zero, to avoid multiple initialization of the operators collection.

[abeham]

r6939

• Added hiding of Maximization parameter
• Fixed AfterDeserializationHook in KnapsackProblem
• Ported ArtificialAntProblem to use the SingleObjectiveHeuristicOptimizationProblem base class

[abeham]

r6942

• fixed problem with ArtificialAntProblem