[IMP]hr_timesheet_invoice : product is not mandatory at the time of creation invoice of expenses and in invoice set product price on the basic of analytic line not on the basis of product price
[MERGE] sync
[FIX] hr_timehseet_invoice: allow use force product
allow using price of 0 or less for expense
[MERGE] [FIX] hr_timesheet_invoice: use invoice amount instead of product and product not mandatory