[IMP] add default order parameter to list views

List views can now be sorted by default with a simple keyword 'order'.
For example

...
<field name="arch" type="xml">
    <tree string="Product Variants" order="name">
        <field name="name"/>
        ...
[IMP] add default order to kanban views

Now, the kanban view can be sorted by any field by default.  It just
needs to be given in the xml descriptor.  For ex,

<field name="arch" type="xml">
    <kanban order="country_id">
[IMP] improves the default order parameter

It is renamed 'default_order' and now supports the usual syntax for
sorting fields: for example 'field1, field2 desc, field3 asc'
Merge remote-tracking branch 'odoo/master' into master-default-order-list-ged
[IMP] improves sorting mechanisms in datasets

Create a deserialize_sort method and add a set_sort method to
datasets.  The set_sort method is useful to avoid duplicating code
in lists and kanban views (to set the initial default order)
Merge remote-tracking branch 'odoo/master' into master-default-order-list-ged
Merge remote-tracking branch 'odoo/master' into master-default-order-list-ged
Merge pull request #520 from odoo-dev/master-default-order-ged

[MERGE] Add support for per-view default order in list/kanban views (task #8527)