Merge branch 'master' into new_timeline

.gitignore

src/Makefile.am

src/cache.h

src/engine.c

src/hydro/Gadget2/hydro_iact.h

src/kernel_hydro.h

src/logger.c

src/logger.h

src/runner.c

src/runner.h

src/runner_doiact_vec.c

src/runner_doiact_vec.h

src/swift.h

src/tools.c

src/tools.h

src/vector.h

tests/Makefile.am

tests/test27cells.c

tests/test27cells.sh.in

tests/test27cellsPerturbed.sh.in