SPH properties are now read from the parameter file

examples/UniformBox/uniformBox.yml

examples/main.c

src/Makefile.am

src/cell.c

src/const.h

src/engine.c

src/engine.h

src/hydro/Gadget2/hydro.h

src/hydro/Gadget2/hydro_io.h

src/hydro_properties.c

src/hydro_properties.h

src/kernel_hydro.h

src/potentials.h

src/runner.c

src/swift.h