***Variables**: Fix nesting variables leads to exception and missing refresh [#13628](https://github.com/grafana/grafana/issues/13628)
***Variables**: Prometheus: Single letter labels are not supported [#13641](https://github.com/grafana/grafana/issues/13641)
***Graph**: Fix graph time formatting for Last 24h ranges [#13650](https://github.com/grafana/grafana/issues/13650)
***Playlist**: Fix cannot add dashboards with long names to playlist [#13464](https://github.com/grafana/grafana/issues/13464), thx [@neufeldtech](https://github.com/neufeldtech)
***HTTP API**: Fix /api/org/users so that query and limit querystrings works
