[IMP] account/sale/sale_layout: standardization of Quotation/Sale Order/Invoice printed layout + add missing information

- Column alignment and order are now uniform across those reports.
- Display Due date on invoices.
- Display payment term and fiscal positions notes.
[IMP] graph view on contacts
[FIX] sell future events only, not old ones
[IMP] website_sale : Don't show shipping address when only services are into shopping cart.
work on pivot view
work on loading groups
work on expand headers
work
work in progress
remove web_graph addon
wip
work in progress
work in progress
work on graph view
add pivot view to leads analysis
work on pivot/graph view
work on export xls
work on pivot/graph split
separate graph view and widget
make better use for context