stock: wrong use of form/tree_view_ref in context

[Alexandre Fayolle - camptocamp]

in stock_view.xml the following views:

* view_picking_form
* view_picking_out_form
* view_picking_in_form

display the move lines using a context containing :

{'form_view_ref':'view_move_picking_form', 'tree_view_ref':'view_move_picking_tree'}

This is incorrect (cf lp:1214799) and must be replaced with

{'form_view_ref':'stock.view_move_picking_form', 'tree_view_ref':'stock.view_move_picking_tree'}