Re-routing should not add new saved entries

A user reports:

> When I miss a turn and get re-routed, I would really appreciate it if all the new routes weren't added to my route history.

This is correct - we shouldn't auto-add these. I think only the original plan should ever be added, because they represent the real user intention, whereas re-routing is often just because of missing a turn or making an unplanned diversion.