OPT: added slicereg2d_affine
OPT: added slicereg2d_affine

Former-commit-id: 1ada5c7f5dc9b15da5d0fccafddbb18823682562 [formerly 8d5483078c0bf14d02dfc439b651da5d5b5866c6]
Former-commit-id: d2b899cd320e906950f5a0e648497e40daccbaed
Former-commit-id: 9f3fa3dc422e9dfcbf8d3f595ddf0aa7b5b0606f
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox