Refs #9476 - While we're here, use new logger.
Refs #9476 - Add "deprecated" function/class decorator.
Refs #9476 - Clean up ISISCommandInterface.
Refs #9476 - Clean up SANSUtility.
Refs #9476 - Get rid of "START/END OF REMOVED" comments.

Version control should be used to see what was changed, when, and by whom.
Merge branch 'feature/9476_deprecate_unused_code' into develop