Pack the timebin for the limiter communications

src/Makefile.am

src/cell.h

src/cell_pack.c

src/cell_unskip.c

src/engine_maketasks.c

src/engine_marktasks.c

src/runner.h

src/runner_main.c

src/runner_pack.c

src/scheduler.c

src/scheduler.h

src/task.c

src/task.h

tools/analyse_runtime.py

tools/task_plots/iplot_tasks.py

tools/task_plots/plot_tasks.py

tools/task_plots/swift_hardcoded_data.py