Merge branch 'master' into timebin_optimization

configure.ac

examples/SineWavePotential_1D/makeIC.py

examples/SineWavePotential_1D/plotSolution.py

examples/SineWavePotential_1D/run.sh

examples/SineWavePotential_1D/sineWavePotential.yml

examples/SineWavePotential_2D/makeIC.py

examples/SineWavePotential_2D/plotSolution.py

examples/SineWavePotential_2D/run.sh

examples/SineWavePotential_2D/sineWavePotential.yml

examples/SineWavePotential_3D/makeIC.py

examples/SineWavePotential_3D/plotSolution.py

examples/SineWavePotential_3D/run.sh

examples/SineWavePotential_3D/sineWavePotential.yml

src/Makefile.am

src/const.h

src/hydro/Gizmo/hydro.h

src/hydro/Gizmo/hydro_gradients.h

src/hydro/Gizmo/hydro_iact.h

src/hydro/Gizmo/hydro_io.h

src/multipole.h