OPT: displays the slices number in the terminal window
OPT: displays the slices number in the terminal window

Former-commit-id: 9df1d4e0e6cc49bba5390382e73c911728725569 [formerly 01f017d684e48ec0222ec61d96d0210653c0ee7d]
Former-commit-id: 002a7042b796917945d04af739e3367e6a81b5ac
Former-commit-id: 138a39a1ff31c2b8a1ee6e18b3e4fa91c1832be9
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox