[FIX] account: avoid losing product on invoice

Add restriction on product_id field to prevent the suppression of the product
if already present in an invoice.
This is to avoid the suppression of a used product variant when modifying
the list of attributes.#
Due to the constrain, the variant will be disabled instead of deleted.
Fixes #4129

Add warning message on the product form to warn users about the potential impact
of modifying variants.
[IMP] account: bank statement reconciliation widget: remove a created line by clicking on it
[FIX] account: bank statement reconciliation widget: do not propose partial reconciliation if there are created lines
[FIX] kanban: respect default_order when a groupby is active

The `default_order` attribute of a <kanban> view was applied
for a non-grouped kanban view, but was simply ignored when
the kanban view was grouped, a common situation.
When a groupby is active, the main order is the column being
grouped, but the `default_order` is still useful as
a secondary sort ordering, within the kanban columns.

This patch complements the original patch of
rev. 5c0804eaef81c237043844382d6456656070fb9f from PR #520.
[FIX] account,sale: show payment term & fiscal position notes in reports

Complete commit 3d88a60
Display payment terms or fiscal position note instead of simple the name.
Fixes #3635
[FIX] purchase: display only one shipping address

The warehouse location is the fallback value
Fixes #4056
[FIX] purchase: access rights when validating a picking

When a warehouse user transfer an incoming shipment, the linked purchase order
is updated as well but the user may not have access to it.
Trigger the workflow as admin instead. opw 619775
[FIX] web: retro compatible patch for a8f94a59cde1c4034b1a704014d1572598db833f

Some views are not appended to the element oe_view_manager_body, such as client actions views.
For these cases, we append the element to the view manager element

Besides, we set the appendTo option of jquery ui autocomplete after a first initialization, because of a Jquery ui bug:
http://bugs.jqueryui.com/ticket/8858
[MERGE] l10n_ch: update the Swiss chart of account to the 2015 version

Also adds 2 financial reports: Balance sheet, Profit and Loss
Fixes #3992
[FIX] sale: copy sales team on the invoice from a sale order

Follows 31a01ea, propagation of some fields from sales orders to invoices (when
created on deliveries) have been added but it missed the section_id field (Sales Team).
Fixes #4155