VNS: benefit from delta evaluation and validation when shaking

[hdbeukel]

Before VNS launches a new iteration of the applied local search procedure, after shaking, it now calls setCurrentSolution(sol) to provide the shaked solution sol as initial solution to this local search. Therefore, the solution is evaluated and validated from scratch.

Suggested change: apply delta evaluation and validation to move used for shaking and set initial solution using the protected method updateCurrentAndBestSolution(sol, eval, val). This will improve the efficiency of shaking in VNS, for applications where an efficient delta evaluation/validation is provided in the problem definition.

[hdbeukel]

Cannot access updateCurrentAndBestSolution(sol, eval, val) but can use the new public method setCurrentSolution(sol, eval, val).