Get clients to use a better default position for new records
By default if the editable option is not define on a tree view, the clients put new record at the bottom. This may not be the desired behavior for example many documents are ordered by descending dates (and ids) like the sale, invoice and purchase.
Also on sao, when a new record is added at the bottom when the user switch back to the list view, sao has to read all the record to the bottom to display it.
I think we could provide a better default behavior (not perfect but at leaste better) if the server send the default order when the action window does not have one and also on the definition of the xxx2many.
This way the client could search for the clause about the id and decide to put new record at the bottom or on top. This is based on the idea that we always set an order for 'id' that matches the expected behavior of creating new record. And if there are no clause for 'id' we keep the current behavior.