The particle definition is now split in multiple files. The correct one gets imported depending on the chosen hydro model.

Extracted the physics from the tasks into a new set of files. The correct file is included when the hydro or gravity models are selected in const.h

Update single node task plots

Update the non-MPI task plot scripts to offer same speed ups as the MPI versions.

See merge request !83

Fix MPI tag collision Issue #68

Increased the maximum cell tag to 2^29 to prevent the MPI tag collision issue #68.

See merge request !82