INST: now display full verbose for mkdir INSTALL_DIR
INST: now display full verbose for mkdir INSTALL_DIR

Former-commit-id: 3a52ac88dd05c7602cb3d90dd9cda1786d5de561
Former-commit-id: b78b2129b961c8128caae588931164df88774ff0
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox