[FIX] strange draggable behavior in Chrome 15/Linux

dragging any other row than the first one in a sortable table (table with sequences)
has the row going way to the right of the table, in both editable list views (e.g.
tasks) and relational fields (e.g. Accounting > Configuration > Financial Accounting
> Taxes > Taxes[form] > Child Tax Accounts

bzr revid: xmo@openerp.com-20120127091938-z79e7aj6wjcmfmmz

addons/web/static/src/js/view_list.js

@@ -1355,6 +1355,7 @@ openerp.web.ListView.Groups = openerp.web.Class.extend( /** @lends openerp.web.L
             axis: 'y',
             items: '> tr[data-id]',
             containment: 'parent',
+            helper: 'clone',
             stop: function (event, ui) {
                 var to_move = list.records.get(ui.item.data('id')),
                     target_id = ui.item.prev().data('id'),