[6.1] hr_timesheet_invoice: Analytic lines created by confirmed customer invoices are also marked to be invoiced

When I confirm invoices created by pressing "Create invoice" button from Analytic account view (see scr1.png), OpenERP generates analytic lines also marked to be invoiced. So, after creating an invoice, "Lines to invoice" view correctly hides the source analytic lines, but show newly generated lines linked to invoice, which I think is not correct.

I propose a small patch to hr_timesheet_invoice.py (specifically to account_move_line class) which disables setting the "to_invoiced" field for analytic lines posted to sale journals (attached patch.diff).