This commit impact crm, website, website_sale and web_planner modules because it
- add planner for website and website_sale
- improve planner notebook by setting texterea and input size to 100% and using col-md-* class
- split js code into common part (used in backend and frontend) and backend part (only for backend)
- adapt some tour, since every page will have the planner modal in its DOM, the tour selectors msut be more accurate
- introduce some style fixes and adaptations
- ...

The module system needs to know the dependencies of a given module
before executing the function.  This is why the dependencies were
defined once in an array, and then were described one more times in the
call to require.

But a trick can simplify this: the boot function can parse the string
representation of the module and extract the calls to require from it.
It is more work for the processor, but it leads to simpler module
definitions.

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