Merge branch 'master' into mpi_periodic_gravity

.gitignore

examples/ConstantCosmoVolume/Gadget2/README

examples/ConstantCosmoVolume/Gadget2/constant_volume.param

examples/ConstantCosmoVolume/README

examples/ConstantCosmoVolume/constant_volume.yml

examples/ConstantCosmoVolume/getGlass.sh

examples/ConstantCosmoVolume/makeIC.py

examples/ConstantCosmoVolume/run.sh

examples/SantaBarbara/README

examples/SantaBarbara/getIC.sh

examples/SantaBarbara/santa_barbara.yml

examples/SmallCosmoVolume/Gadget2/README

examples/SmallCosmoVolume/Gadget2/small_cosmo_volume.param

examples/SmallCosmoVolume/README

examples/SmallCosmoVolume/small_cosmo_volume.yml

examples/SmallCosmoVolume/stf_input_6dfof_dmonly_sub.cfg

examples/ZeldovichPancake_3D/plotSolution.py

examples/ZeldovichPancake_3D/zeldovichPancake.yml

src/engine.c

src/hydro/Gadget2/hydro.h