Merge branch 'fight_the_power' into 'master'

replace ** with clearer operators where possible

See merge request !149
5 jobs for master in 11 minutes and 23 seconds (queued for 1 second)
Status Name Job ID Coverage
  Test
passed test_min #185295

00:02:22

passed test_mpi #185296

00:03:57

passed test_mpi_fftw #185297

00:04:01

passed test_mpi_fftw_hdf5 #185298

00:05:21

57.0%
 
  Release
passed release_image_master #185299

00:06:01