INST: install_sct: manage case of installation to another folder
INST: install_sct: manage case of installation to another folder

Former-commit-id: 7f23f4431290ab04ab1b63b40499c386c94a7b12 [formerly b873ffec7a31f0a0699915ee80e704a7b0725a63]
Former-commit-id: 796cf39ab69c4a9587f5a6e3b56be4993e42f1c4
Former-commit-id: 73d86212c3b8e822e8a11bc6fd7b3e15b2b7a0a5
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox