Merge branch 'doself2-vectorisation' into dopair2-vectorisation
Conflicts: src/hydro/Gadget2/hydro_iact.h src/runner_doiact_vec.c src/runner_doiact_vec.h tests/test125cells.c
Conflicts: src/hydro/Gadget2/hydro_iact.h src/runner_doiact_vec.c src/runner_doiact_vec.h tests/test125cells.c