Added update of Nsph and Nstar field in the diagnostic structure
Added Box structure; converted boxes inside MpiNode to the new structure; modified function in MpiControl to update h bounding boxes on all nodes; added code in MpiControl constructor to create a custom MPI datatype for boxes
Added helper functions to know if two rectangles overlap or if a sphere and a rectangle overlap
Small bug fixed in hbox computation
Added MPI write routine for column format
Added call to MPI_Finalize inside the main function
Moved back itype from SphIntParticle to SphParticle structure