Support unhomogeneous palletization/packing with several blocks...

[fgasnier71]

Modify the engine in order to support palletization with several rectangular blocks in which the box/case might have different orientations. The strategy consist in partitioning the area in 2 or 3 blocks with different orientation on neighboring blocks and in incrementing the size of one of the blocks by the smallest dimension of the box/case before running the engine on each block. Need to add some drawings.