Merge branch 'master' into mpi_periodic_gravity

examples/ZeldovichPancake_3D/plotSolution.py

examples/ZeldovichPancake_3D/run.sh

examples/ZeldovichPancake_3D/zeldovichPancake.yml

examples/parameter_example.yml

src/Makefile.am

src/cell.c

src/cosmology.c

src/cosmology.h

src/debug.c

src/engine.c

src/engine.h

src/equation_of_state/planetary/aneos.h

src/equation_of_state/planetary/equation_of_state.h

src/equation_of_state/planetary/get_eos_tables.sh

src/equation_of_state/planetary/hm80.h

src/equation_of_state/planetary/sesame.h

src/equation_of_state/planetary/tillotson.h

src/hydro.h

src/hydro/Default/hydro.h

src/hydro/Gadget2/hydro.h