agile: close sprint 48
agile: open sprint 49
roadmap: remove the road map

After some consideration, we have decided that the road map has more
downsides than upsides, so it has been removed.
agile: design an end-to-end solution to the tag problem

- update all the stories in light of the tag solution; generate
  sensible, short stories to implement it.
- move stories to backlog that we don't think we'll be working on