[IMP]website_quote: improve quotation empty list menutip, add template menu tip, improve mobile preview by css, highlight button according to quotation viewed or not. fix typo

Hello
improve quotation empty list menutip, add quotation template menutip, improve mobile preview by css, highlight button according to quotation viewed or not, replace openerp by odoo in templates, fix typo quote to quotation.
More Details:
Task: https://www.odoo.com/web#id=8070&view_type=form&model=project.task&menu_id=3942&action=327
Pad : https://pad.odoo.com/p/r.BsD4C9cp0A5Vu0Is
Thanks
I think there is already a task trying to simplify the various templates. Could we remove this change, so that the other task handle templates, and this one cleans the wording ?