[FIX] web: expose list view Column widget
[FIX] web: expose list view Column widget

The list view Column widget should be exposed, so it can be extended.
This is required to allow the creation of other kind of list widgets.
The _format method is not extendable if we don't add this line.

(comment from ged) The file list_view.js should be split in two, and
reorganized, but this should not be done in 9.0.

dfang/odoo,dfang/odoo,Elico-Corp/odoo_OCB,bplancher/odoo,hip-odoo/odoo,microcom/odoo,storm-computers/odoo,sysadminmatmoz/OCB,bplancher/odoo,microcom/odoo,sysadminmatmoz/OCB,bplancher/odoo,bplancher/odoo,dfang/odoo,Elico-Corp/odoo_OCB,laslabs/odoo,ygol/odoo,ygol/odoo,storm-computers/odoo,storm-computers/odoo,Elico-Corp/odoo_OCB,storm-computers/odoo,dfang/odoo,hip-odoo/odoo,hip-odoo/odoo,bplancher/odoo,Elico-Corp/odoo_OCB,sysadminmatmoz/OCB,laslabs/odoo,hip-odoo/odoo,laslabs/odoo,ygol/odoo,dfang/odoo,Elico-Corp/odoo_OCB,hip-odoo/odoo,ygol/odoo,microcom/odoo,sysadminmatmoz/OCB,sysadminmatmoz/OCB,hip-odoo/odoo,sysadminmatmoz/OCB,dfang/odoo,Elico-Corp/odoo_OCB,microcom/odoo,ygol/odoo,bplancher/odoo,microcom/odoo,microcom/odoo,laslabs/odoo,storm-computers/odoo,laslabs/odoo,ygol/odoo,storm-computers/odoo,sysadminmatmoz/OCB,laslabs/odoo,ygol/odoo