NEW: -added alto slicered2d_syn and slicereg2d_bsplinesyn -added detection and deletion of outliner for regularization along z
NEW:
-added alto slicered2d_syn and slicereg2d_bsplinesyn
-added detection and deletion of outliner for regularization along z

Former-commit-id: f5a053aa6f9b655abc9d5bb263cb424705fcfa43
Former-commit-id: 7fff41b721e2a16c030b919e8936987f06c7dec6
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox