Merge branch 'master' into update_cooling_grackle

examples/EAGLE_12/eagle_12.yml

examples/EAGLE_25/eagle_25.yml

examples/EAGLE_50/eagle_50.yml

examples/EAGLE_6/eagle_6.yml

examples/UniformDMBox/uniformBox.yml

examples/analyse_tasks.py

examples/check_ngbs.py

examples/plot_tasks.py

src/active.h

src/cell.c

src/cell.h

src/collectgroup.c

src/collectgroup.h

src/debug.c

src/engine.c

src/engine.h

src/partition.c

src/proxy.c

src/proxy.h

src/runner.c