* Prettify duration unit format

Format duration like "2 days, 19 hours, 48 minutes" and make Decimals useful e.g.
0 decimals: 2 days
2 decimals: 2 days, 19 hours, 48 minutes
3 decimals: 2 days, 19 hours, 48 minutes, 27 seconds

Previous code did some rounding that is now gone so numbers might be
different.

* Rewrite kbn.toDuration without moment.js

Because https://github.com/moment/moment/issues/3653

* Add tests for kbn.toDuration

Small refactor to make hover highlighting proper, added a title tag for the completed grafana step. (#6882)

Adjusted the active state to fix the faint line showing. Probably related to the font change going into 4.0 (#6886)

Fixed Create org API in docs

Fix some typos in Reference docs

closes #6869

feat(elasticsearch): Added support for Missing option (bucket) for terms aggregation, refactoring PR #4244, thx @shanielh

alerting: add support for OpsGenie

* datasource: move caching closer to datasource struct

* tsdb: use cached version of datasource http transport

closes #6825

issue-id: #5688

Fix docs typo