[FIX] l10n_ma: proper chart of account name
[FIX] stock: display product variant name in the slip
"[REVERT][FIX] point_of_sale: field date of report.pos.order should be a datetime"

This reverts commit 97d097a2af8c3992d5108bd75b82fa8479d196cc.

As explained in the commit comments (on Github), this patch leads to an infinite loop in 7.0, the filter of the pos orders report using the '=' operator in its domain, which is not available for datetime fields, but is for date fields.

This should not be forward ported to newer release (saas-3)
[MERGE] forward port of branch 7.0 up to 18d365c
[FIX] mail: more robust parsing of In-Reply-To/References (OPW 608919)

When parsing incoming messages, ignore white-space around
In-Reply-To headers, and extract message-id items inside
the References header using a regex.
This actually serves as a workaround for broken MTAs
mangling References (such as outlook.com nesting past ones
with commas, violating RFC2822).

Closes #516 as a manual rebase.
[FIX] web: no_create, if loose focus do not open quick_create
[FIX] gamification: performance improvement

On a large database, thousands of badges may have been granted. This code used to prefetch all fields of the users and badge users. This was highly inefficient. Replace this code by SQL query.
[FIX] l10n_be_coda: if there's no communication, feed the field with '/' instead of an empty string
[IMP] sales_team: remove widget many2many_kanban from "Team Members" tab. Need to fix the security check from many2many_kanban before to reuse-it. Was checking delete user, and not write sale_team when we were tyring to delete a sale_men (user) from member_ids.
[IMP] gamification: improve 40e8437 to make only one global request
[IMP] sales_team: Force a tree view in Sales team tab to avoid to show unnecessary informations like last login date
[FIX] website_sale: pay now button should be translatable
[FIX] survey: trace the partner_id taking the survey; if no token, set as the current user's partner.
[FIX] account, bank statement reconciliation: fixed use cases involving transactions made in a different currency than the company AND the statement ones
[ADD] initial theme guide + scaffolding

incomplete, incorrect, committed for testing
[FIX] fields: avoid prefetching of one2many fields

When reading a one2many field, the inverse mapping of the lines (matching m2o -> lines of corresponding record) was instantiating each line and then triggering the prefect of fields.
To improve the performances, the inverse mapping is done in sql to avoid triggering the prefetching.
Forward port of branch saas-3 up to c3f5289
[IMP] fields: update inverse fields lazily for performance

When a relational field is assigned in an onchange, its inverse field is
updated in cache.  Reading the current value of the inverse field may be
costly, for instance in the case of a one2many field with thousands of records
as a value.  Instead, put in cache a SpecialValue that reads and updates the
field; it will be triggered only when it is accessed.
[IMP] models: do not prefetch too many records at once
[IMP] models: prefetch fields with groups (those to which user has access)