crm_departement : a section id change

- on_change_section python code ported from 6.1 + add the saleman in return value, to set the salesman corresponding to the salesteam reponsible.
- remove user_id python code, as it's not call from XML, and selecting a departement base on user_id is not usefull because a user can be on multiple department.
- pep 8 cleaning of the module