Update comments on SCT_FrontEnd
- Update comments on SCT_FrontEnd.
- Add more comments.
- Replace XXX by (1XX|X1X|XX1).
- Rename expanded any hit mode to any hit mode because expanded mode means a different mode.
- Rename SCT_Digitization_jobOptions_expandedmode.py to SCT_Digitization_jobOptions_anyhitmode.py.
Edited by Susumu Oda