BUG: fixed rotation issue of the warping field for straightening. Fixed #419
BUG: fixed rotation issue of the warping field for straightening. Fixed #419

Former-commit-id: 78c8c704472acf0daa11660076fb41c92a94f8de [formerly daa4feba6dc545b77f7892261c2199f08a3df512]
Former-commit-id: f34f1418b14c34a638a54fb460b7ebe3f5623ca6
Former-commit-id: cd52f8798dafdee598a568f2333247f660235395
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox