[FIX] project, project_issue: when no project in context, display default
columns in kanban view. Also fixed some issues in the issue kanban view.
[IMP] crm: opportunity kanban view: display tags.

[FIX] crm: opportunity kanban view: description of a crm stage is requirements
not description.
[IMP] im_livechat : add nbr_sessions field on channel and modifications of various views
[IMP] im_livechat : add rule to display (or not) the support button.
[FIX] fix debug mode: correct id and xml_id (web client)

This commit fixes two issues with debug mode:
* when a default searchview is requested, it is
initialized without its view_id. Problem is that it prevents debug mode from editing the view.
*  add xml_id in Edit action form view(debug mode) : this makes the xml id visible in form view
[FIX] web: radio buttons

removed js that let user to uncheck radiobutton and from addons removed radiobuttons used for not required field except sync_typ.
changed this field as required because of functional requirement
[IMP] mrp: BoM name is now accessible to the 'manage multiple level
of bom' group, not the properties group. Indeed this will allow more users
to see and search the name.
[IMP] stock: onboarding (display improvements)
[REF] stock: product quantity stat button

Clean version of stat button of product quantity. Will also work in
creation mode and avoid unuseful computed string field

(fix parts of commit 52c3b52bf09fea7e0920ebcec3f0e8acb066b2b7)
[REM] product: leftovers of unused field "mes_type"

Also removed in data in point_of_sale, project_timesheet and sale_mrp.
[FIX] stock: correct label for picking_id
[REF] stock: replace <div> in view by nolabel

This patch does not change the look of the view; it is only intended to
use the standard feature "nolabel" instead of hacking the HTML with a
<div> tag.
[REV] stock: partial revert of 52c3b52bf09fea7e0920ebcec3f0e8acb066b2b7

The <div> were introduced to correct alignement issues in this form view. Actually, they are generic and due to inherited invisible group, so CSS is sometimes incorrect when you hide groups. Should be fixed in form view implementation.
[IMP] allow many2many to specify formview (web client)

One2Many fields can specify sub tree and sub form view, to be used when
displaying a list view and when adding/editing an element.  Many2many
can display a sub tree view, but ignore sub formviews.  This can be
fixed by specifying an alternative_form_view to the popup form widget.
[IMP] account: account.statement.operation.template model
- better many2one ondelete strategies
- added analytic account domain
- added multi-company support
[IMP] Replace gantt chart library with dhtmlxgantt 3.1