The "edit" action is on the "website.TopBar", which will create a new
instance of the "editor" (web_editor.editor) widget.
So if we want to do something when the "editing" start, we have to
either override "edit" of the TopBar, or override "start" or "init" of
the editor.
opw-657662
`mass_mailing.unsubscribe` depends on
1. `web.ajax`, as it uses `ajax.jsonRpc`
2. `web_editor.base`, to explicitely wait
for all dependencies to be loaded,
so the DOM can contain `o_unsubscribe_form`
opw-654396
Each module can return a deferred. In that case, the module is marked as loaded
only when the deferred is resolved, and its value is equal to the resolved value.
The module can be rejected (unloaded). This will be logged in the console as info.
Remove if_dom_contains from the website, the modules return a rejected deferred if
the DOM doesn't contains the seleted values.
qsm-odoo