- Preserved explicit 3rd-party copyright notices
- Explicit boilerplate should not be necessary - copyright law applies
  automatically in all countries thanks to Berne Convention + WTO rules,
  and a reference to the applicable license is clear enough.

This module allow to make versioning and A/B testing of the website.

With more than 100 comments on github[1], this commit is clearly not
production-ready.

This reverts commit c255b5bc3461c803e38057c72c45530235de84dd, reversing
changes made to e5ac65de59f45f2d15ae6f6b840b02cac78afd03.

[1] https://github.com/odoo/odoo/commit/c255b5bc3461c803e38057c72c45530235de84dd