Merge branch 'master' into star_formation_mpi

examples/EAGLE_ICs/EAGLE_25/README

examples/EAGLE_ICs/EAGLE_25/eagle_25.yml

examples/EAGLE_ICs/EAGLE_25/getIC.sh

examples/EAGLE_ICs/EAGLE_25/run.sh

examples/EAGLE_ICs/EAGLE_50/README

examples/EAGLE_ICs/EAGLE_50/eagle_50.yml

examples/EAGLE_ICs/EAGLE_50/getIC.sh

examples/EAGLE_ICs/EAGLE_50/run.sh

src/cell.c

src/engine.c

src/engine_marktasks.c

src/runner.c

src/runner_doiact_stars.h

src/space.c

src/space.h

tools/combine_ics.py