[crm] implementation planner

- Task: https://www.odoo.com/web/#id=8592&view_type=form&model=project.task&menu_id=3942&action=327
- Pad: https://pad.odoo.com/p/r.4BHh6hQdZ4GPR2qE
The qweb template for js must be in the manifest __openerp__.py with the 'qweb' key. It will be load when /webclient/qweb will be called. So it keeps only on rpc call for all the widget templaltes.