Added button pick lower\higher labels
Added button pick lower\higher labels


Former-commit-id: 319f8ddab7d0a8832b2914c48bb5bc6c5ea457f7
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox