[Quote builder] print to pdf 

- Task: https://www.odoo.com/web#id=9286&view_type=form&model=project.task&action=333&active_id=131
- Pad: https://pad.odoo.com/p/r.J3mShCzM9sV03MEw
Qweb report should be produced by wkhtmltopdf 0.12.1 with patched qt (see http://wkhtmltopdf.org/)