Merge from nse back-end partial picking wizard
[FIX] better responsibilities on objects POS
[FIX] recursion
[FIX] difference POS / Cash
[IMP] readable code
[FIX] web: fixed css of hidden input file: a hidden element could interfere with other elements
in the dom, leading to some fields not being accessible.
[FIX] ir_actions: server action: check the validity of write_expresison only if defined. Also check for the related model only if set in the onchange.
[FIX] ir_actions: server action: when creating or writing value on a record
through a server action, try to correctly set the value to write on a given
fields according to its type. For example many2one fields should receive an
int, not a unique containing the id of the new value.
[IMP] Graph views: show always measure + filters record measures in context
[IMP] board: do not filter actions anymore

Starting from v8.0, there's only "My Dashboard". We can assume that we
have access rights to all the actions we pin to our proper dashboard, so
we can remove this filtering. Furthermore, this was a large performance
pitfall.
[IMP] Usability improvements by clarifying texts
[IMP] lazy loading of dashboards

The widget AddToDashboard used to make an ajax call every time the
search view is loaded.  This is often useless and can be annoying when
that request is long.  With this patch, the request is only done when
the user click on the widget AddToDashboard
[IMP] point_of_sale: add missing functionality necessary for the loyalty module
[FIX] fields: add missing option 'sanitize' on Html fields
Merge pull request #1888 from odoo-dev/8.0-wmsnsewiz-jco

Merge from nse back-end partial picking wizard
[IMP] models: move prefetching of records back to method _prefetch_field

The selection of records in cache for prefetching was moved to method
_read_from_database() by xmo at rev 785018cc in order to fix an access right
bug.  But this introduced an issue: to explicitly avoid prefetching, you should
use read() instead of browsing records.  We revert the change by xmo, without
reintroducing the bug (which apparently was fixed by another way).