Moved 3BKP Multi3BKP SMALLHULL in the same branch + Improved report and add Benchmark results

Fixed Multi3BKP and add new problem the hull3BKP. Major refactoring of code.

Split the optimization of the profit (Master Problem) and the optimization of the chi values (Optional Problem).
Re-Introduced the possibility to add the balancing constraints (extended for the multiknapsack) variant.
Major refactoring of the code that will permit to keep the interface Master Problem and attach another implementation for the last assignment

Drafted and implemented multiknapsack version of the 3BKP with a modified objective functions that tries also to minimize the coordinates of the items inside an object. Added possibility to view the selected knapsacks in the 3D space.

Modified the objective function so that it tries to minimize the chi coordinates. Because the process could be extremly slow the timeout option was added. In order to optimize w.r.t. to only some directions one can disable the x-axis optimization (through the option -x) y-axis (through the option -y) and z-axis (through the option -z).

The constraint 16 was modified so that also objects bigger than the knapsack can be included in the list. This step is fundamental for a future Multi-Knapsack extension