In verbose mode, commands first print the updated task, then summarize the change in the following line.
The add/addm/addto commands deviated from this, using "TODO: '<task>' added on line N."
This change splits this into two separate lines, obsoletes the implementation jargon of "line", and makes it easier to visually parse the message.
This is also a preparation for a possible future use of a _list()-like function, so that the updated task is processed and highlighted like the normal task output.
