[MERGE] Forward-port 9.0 up to b64b9619

addons/base_import_module/models/ir_module.py

addons/crm/__init__.py

addons/crm/controllers/__init__.py

addons/crm/controllers/main.py

addons/crm/crm_lead.py

addons/hr_holidays/__init__.py

addons/hr_holidays/controllers/__init__.py

addons/hr_holidays/controllers/main.py

addons/hr_holidays/hr_holidays.py

addons/mail/controllers/main.py

addons/mail/models/mail_thread.py

openerp/addons/base/res/res_users.py

openerp/tools/convert.py