Do the same change for the kick1/time-step/kick2 combo

src/cell.c

src/cell.h

src/engine.h

src/engine_maketasks.c

src/engine_marktasks.c

src/space.c

src/task.c

src/task.h

tools/task_plots/analyse_tasks.py

tools/task_plots/iplot_tasks.py

tools/task_plots/plot_tasks.py