***S3 Image Store**: External s3 image store (used in alert notifications) now support AWS IAM Roles, closes [#6985](https://github.com/grafana/grafana/issues/6985), [#7058](https://github.com/grafana/grafana/issues/7058) thx [@mtanda](https://github.com/mtanda)
***Optimzation**: Never issue refresh event when Grafana tab is not visible [#7218](https://github.com/grafana/grafana/issues/7218), thx [@mtanda](https://github.com/mtanda)
***Browser History**: Browser back/forward now works time ranges / zoom, [#7259](https://github.com/grafana/grafana/issues/7259)
***SingleStat**: Implements diff aggregation method for singlestat [#7234](https://github.com/grafana/grafana/issues/7234), thx [@oliverpool](https://github.com/oliverpool)
## Bugfixes
***Alerting**: Fixes missing support for no_data and execution error when testing alerts [#7149](https://github.com/grafana/grafana/issues/7149)
