[FIX] Correctly stop embedded form when switching from editable to non-editable list
[FIX] Correctly stop embedded form when switching from editable to non-editable list

When using the ``set_editable`` feature (context key) from filters
(togglable on/off), the list view would not correctly clean up
(destroy) the form when switching from editable with a started editor
(and form) to non-editable, leading to form fields (in this case m2o
fields being in an incorrect state and trying to query a non-started
autocompletion widget on every click anywhere blowing it up).


akretion/openerp-web,akretion/openerp-web,havt/openerp-web,havt/openerp-web,akretion/openerp-web,havt/openerp-web,havt/openerp-web,havt/openerp-web