create/update user email
drop support for artificial users
progress on password reset
fix captcha
Merge branch 'master' into email

* master:
  fix captcha
password reset WIP
password reset WIP
api json 404
Merge branch 'master' into email

* master:
  api json 404
Add Uyghur to language list.
fix puzzle move indicator after wrong move
complete password recovery procedure
Merge branch 'email'

* email:
  complete password recovery procedure
  fix puzzle move indicator after wrong move
  password reset WIP
  password reset WIP
  progress on password reset
  drop support for artificial users
  create/update user email
fix password recovery unknown email
fix miniboards in 3D env
remove square effect transition on mini boards
opening trainer model, API, importer and DB
open import API for opening training
opening training API fixes
compress DB opening lines in binary PGN format