Banks are using this term: _Payment reference_. This is more what we are aiming for. - [x] Rename CLI option: `silkaj money transfer -c/--comment` −> `-ref/--reference`. `-r` is already used by `--recipient` - [x] Rename UI fields of `transfer` and `history` commands - [x] Adapt run time code and tests. Keep `comment` interface when using DuniterPy document, that’s what we won’t change.