Merge branch 'master' into space_docu

# Conflicts:
#	nifty/spaces/rg_space/rg_space.py
4 jobs for space_docu in 6 minutes and 28 seconds (queued for 22 seconds)
Status Name Job ID Coverage
  Test
passed test_min #164409

00:01:33

passed test_mpi #164410

00:03:03

passed test_mpi_fftw #164411

00:03:44

passed test_mpi_fftw_hdf5 #164412

00:04:39

47.0%