[IMP] Cache bundles in ir.attachments instead of a LRU

Forward ported from 8.0's commit: 8402625
[FIX] mail: bad test
[IMP] hr: strenghtening of write()
[IMP]website_quote: replace openerp by odoo in templates, improve quatation emptylist, improve mobile preview by css, add template empty list menutip.

[IMP]add quote_viewd field to check quote is viewed first time and change highlight button accordingly