Before this commit, 'select all' into a list view, and use an action that assign
a user_id to all the records will send n² email, because the function send_mail
use active_domain instead of the current record.
Now, we keep mass_mail mode, but simulate the case where we have clicked on
each record one by one and not all the records matching the active_domain.
So we send only one email by record.
How to reproduce:
create a action server "record.write(dict(user_id=env.user_id))"
add this action in context menu
select all records in a list and apply the action server
Jeremy Kersten
3f267a5951