* Prevent different identities from a same SSO provider from accessing a same account

* Lock auth provider changes behind `ALLOW_UNSAFE_AUTH_PROVIDER_REATTACH=true`

* Rename methods to avoid confusion between OAuth and OmniAuth

* fix: change Identity's id column to a bigint

This appears to be the last model created using a 5.0 migration,
where column types defaulted to `integer` rather than `bigint`.

This migration changes the column type to match that of all of the
other ID columns.

* Change user_id column in identities to bigint and fix down-migration

* Cas authentication feature

* Config

* Remove class_eval + Omniauth initializer

* Codeclimate review

* Codeclimate review 2

* Codeclimate review 3

* Remove uid/email reconciliation

* SAML authentication

* Clean up code

* Improve login form

* Fix code style issues

* Add locales