[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
typo: "overlaps"