Also check for plus sign only to be visible when necessary,
which makes quantity unnecessary when handling serial numbers

The function field selected_seller_id is removed  and must be replaced
by a direct call to method `_select_seller`. This is more conventional
than the previous 'browse with context' way of doing.

We introduce a new field on supplierinfo: product_id. Thanks to this
field, the vendor information which will be used in a purchase order can
be specific to the product variant.

Revert till several issues are solved.

update summernote library up to revision:
 https://github.com/summernote/summernote/commit/a0f26e300

see https://github.com/summernote/summernote/ for history

closes #8704

Without cash control the pos_session workflow automatically sets session
states to 'open' (and so they skip 'opening_control'). With cash control
enabled however this does not happen.
8a232e7f removed a button which allowed
you to open the session. This adds back a simplified button which
appears when necessary and just sets the state to 'open'.

(backport of enterprise version)

* JS/XML refactoring
* Allow user to override default options for the picker

Read more / less feature is back (and probably ugly). It has probably been
removed when refactoring the old chatter.

[FIX] tools: html shortening: encoding issue

You usually do not need to change the pricelist when you are browsing a blog or a normal website, so this menu should only be visible in the webshop

* As the animations were already defined in web_planner, they are now moved in web (animations.less)

Before this commit, when editing a line in a listview editable, the
record selector (checkbox) lost its state after the line edition.

Elements which are not displayed (display: none) cannot be positionned
correctly by jQueryUI in a listview editable. Therefore, the solution is
to make them visible (but opacity: 0) during the time their position is
being computed.

This was a problem because a listview editable field may become visible
under some conditions AFTER their position was already computed.

To re-order the list view remove the record and add the same record after.
(If an onchange is called, the user can have a message to avoid remove a one2many item)
Add an silent option on remove function of collection, the trigger is already call when write the sequence.

Some widgets like list editable use and change values dictionary. When the write is called, the values in the cache is equal to the changes send => field no dirty => no change triggered.

missing spaces or unclear help messages

[IMP] web_editor: usability: allow saving even when nothing was changed when editing in the frontend

- fixes product ordering in shop page
- fixes "sale" ribbon that was un-removable

As the new messaging system has been deployed, this needs to be fixed later

* 'Help' has now its own dropdown, directly accessible in the systray, instead of being hidden in the Administrator dropdown
* 'About' has been moved there also
* We can access the planner through this dropdown, even if the planner is hidden (complete)

[FIX] orm, fields: read_group on monetary fields now correctly makes the sum instead of ignoring them

[IMP] account: added a test on invoice validation to avoid duplicated reference on vendor bills and refunds, because it's probably a double encoding of the same document

[FIX] web_editor & website: don't display edit placeholder if the node have class oe_no_empty or oe_not_editable

Don't need to add the empty value because ir_translation generate missing values automatically.
(bug e.g.: Link with empty string can't be clicked)

The field 'state' has been removed, so this is now useless.