glicko engine and migration WIP
Merge branch 'master' into glicko

* master:
  unset empty players after migration
  write winner color in game object + mongodb migration script
glicko migration WIP - seems like the glicko lib aint' working right
Merge branch 'master' into glicko

* master:
  upgrade reactivemongo and fix games winner ID
  fix user collection
  nb "Norsk bokmål" translation #5602. Author: Mangi.
  sw "Kiswahili" translation #5601. Author: Mangi.
  ru "русский язык" translation #5597. Author: Anonymous. the translation is great, I just deleted an unnecessary comma. thank you

Conflicts:
	todo
glicko2 migration WIP
convert all site to glicko ratings
improve rating system
migrate game collection with glicko ratings
Merge branch 'master' into glicko

* master:
  update todo
  ru "русский язык" translation #5611. Author: myadzel@gmail.com. https://github.com/ornicar/lila/commit/0e24395252870a218cc6f29209aeebb8112eb23c#commitcomment-4880001
  hy "Հայերեն" translation #5608. Author: Միքայել.
  other ko translation
  update todolist + minor tweaks
  ko "한국어" translation #5606. Author: xnuk. 한국어 기여 좀 해주세요 ;ㅅ;
  ko "한국어" translation #5605. Author: Anonymous.
  eo "Esperanto" translation #5604. Author: Timwi.
  pt "Português" translation #5603. Author: NotReally.

Conflicts:
	todo
fix double dash in game url
upgrade chess module
be more tolerant when elasticsearch is missing
stop scheduling when actor system is closing